Electromagnetic flow regulator, system, and methods for regulating flow of an electrically conductive fluid

ABSTRACT

Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.

BACKGROUND

This application generally relates to regulating flow of an electricallyconductive fluid.

SUMMARY

Disclosed embodiments include electromagnetic flow regulators forregulating flow of an electrically conductive fluid, systems forregulating flow of an electrically conductive fluid, methods ofregulating flow of an electrically conductive fluid, nuclear fissionreactors, systems for regulating flow of an electrically conductivereactor coolant, and methods of regulating flow of an electricallyconductive reactor coolant in a nuclear fission reactor.

In addition to the foregoing, various other method and/or device aspectsare set forth and described in the teachings such as text (e.g., claimsand/or detailed description) and/or drawings of the present disclosure.

The foregoing is a summary and thus may contain simplifications,generalizations, inclusions, and/or omissions of detail; consequently,those skilled in the art will appreciate that the summary isillustrative only and is not intended to be in any way limiting. Inaddition to the illustrative aspects, embodiments, and featuresdescribed above, further aspects, embodiments, and features will becomeapparent by reference to the drawings and the following detaileddescription.

BRIEF DESCRIPTION OF THE FIGURES

While the specification concludes with claims particularly pointing-outand distinctly claiming the subject matter of the present disclosure, itis believed the disclosure will be better understood from the followingdetailed description when taken in conjunction with the accompanyingdrawings. In addition, the use of the same symbols in different drawingswill typically indicate similar or identical items.

FIG. 1A is a side plan view in partial schematic form of an illustrativeelectromagnetic flow regulator;

FIG. 1B is a side plan view in partial schematic form of anotherillustrative electromagnetic flow regulator;

FIG. 1C is a partial cutaway side plan view of the electromagnetic flowregulator of FIG. 1B;

FIG. 1D is a view taken along section line 1D-1D of FIG. 1C;

FIG. 1E is a magnified fragmentation view in transverse cross section ofa detail of the electromagnetic flow regulator of FIG. 1B;

FIG. 1F is a graph of the relationship of velocity of an electricallyconductive fluid, a magnetic field, and an induced electric field;

FIG. 1G is a partial cutaway perspective view of the electromagneticflow regulator of FIG. 1B;

FIG. 1H is a is a magnified fragmentation view in transverse crosssection of another detail of the electromagnetic flow regulator of FIG.1B;

FIG. 1I is a graph of the relationship of induced current in anelectrically conductive fluid, a magnetic field, and a resultant Lorentzforce;

FIG. 1J is a magnified fragmentation view in perspective cross sectionof another detail of the electromagnetic flow regulator of FIG. 1B;

FIG. 1K is a side plan view in partial cutaway schematic form of anotherillustrative electromagnetic flow regulator;

FIG. 1L is a view taken along section line 1L-1L of FIG. 1K;

FIG. 1M is a view taken along section line 1M-1M of FIG. 1K;

FIG. 1N is a view taken along section line 1N-1N of FIG. 1M;

FIG. 2A is a flowchart of an illustrative method of regulating flow ofan electrically conductive fluid;

FIGS. 2B-2E are flowcharts of details of the method of FIG. 2A;

FIG. 2F is a flowchart of another illustrative method of regulating flowof an electrically conductive fluid;

FIG. 2G is a flowchart of details of the method of FIG. 2F;

FIG. 2H is a flowchart of another illustrative method of regulating flowof an electrically conductive fluid;

FIG. 2I is a flowchart of details of the method of FIG. 2H;

FIG. 3A is a flowchart of an illustrative method of fabricating anelectromagnetic flow regulator;

FIGS. 3B-3K are flowcharts of details of the method of FIG. 3A;

FIG. 3L is a flowchart of another illustrative method of fabricating anelectromagnetic flow regulator;

FIGS. 3M-3P are flowcharts of details of the method of FIG. 3L;

FIG. 3Q is a flowchart of another illustrative method of fabricating anelectromagnetic flow regulator;

FIGS. 3R-3T are flowcharts of details of the method of FIG. 3Q;

FIG. 4A is a schematic illustration of an illustrative nuclear fissionreactor system;

FIG. 4B is a top plan view in partial schematic form of an illustrativenuclear fission module;

FIG. 4C is a top plan view in partial schematic form of illustrativenuclear fission modules of FIG. 4B;

FIG. 4D is a top plan view in partial schematic form of otherillustrative nuclear fission modules of FIG. 4B;

FIG. 4E is a top plan view in partial schematic form of otherillustrative nuclear fission modules of FIG. 4B;

FIG. 4F is a top plan view in partial schematic form of an illustrativetraveling wave reactor core;

FIG. 5A is a schematic illustration of components of an illustrativenuclear fission reactor;

FIGS. 5B-5C are partial cutaway side plan views in partial schematicform of illustrative electromagnetic flow regulators and nuclear fissionmodules;

FIGS. 6A-6C are partial cutaway side plan views in partial schematicform of other illustrative electromagnetic flow regulators and nuclearfission modules;

FIG. 6D is a partial cutaway top plan view in partial schematic form ofan illustrative reactor core;

FIG. 6E is a partial cutaway side plan view in partial schematic form ofthe reactor core of FIG. 6D;

FIG. 6F is a partial cutaway top plan view in partial schematic form ofanother illustrative reactor core;

FIGS. 6G is a partial cutaway side plan view in partial schematic formof the reactor core of FIG. 6F;

FIGS. 6H-6J are partial cutaway top plan views in partial schematic formof other illustrative reactor cores;

FIG. 7A is a flowchart of an illustrative method of regulating flow ofan electrically conductive reactor coolant;

FIGS. 7B-7S are flowcharts of details of the method of FIG. 7A;

FIG. 7T is a flowchart of an illustrative method of regulating flow ofanother electrically conductive reactor coolant;

FIGS. 7U-7AH are flowcharts of details of the method of FIG. 7T;

FIG. 7AI is a flowchart of an illustrative method of regulating flow ofanother electrically conductive reactor coolant; and

FIGS. 7AJ-7AW are flowcharts of details of the method of FIG. 7I.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented herein.

In addition, the present application uses formal outline headings forclarity of presentation. However, it is to be understood that theoutline headings are for presentation purposes, and that different typesof subject matter may be discussed throughout the application (e.g.,device(s)/structure(s) may be described under process(es)/operationsheading(s) and/or process(es)/operations may be discussed understructure(s)/process(es) headings; and/or descriptions of single topicsmay span two or more topic headings). Hence, the use of the formaloutline headings is not intended to be in any way limiting.

Moreover, the herein described subject matter sometimes illustratesdifferent components contained within, or connected with, differentother components. It is to be understood that such depictedarchitectures are merely exemplary, and that in fact many otherarchitectures may be implemented which achieve the same functionality.In a conceptual sense, any arrangement of components to achieve the samefunctionality is effectively “associated” such that the desiredfunctionality is achieved. Hence, any two components herein combined toachieve a particular functionality can be seen as “associated with” eachother such that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected”, or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents, and/or wirelessly interactable, and/or wirelesslyinteracting components, and/or logically interacting, and/or logicallyinteractable components.

In some instances, one or more components may be referred to herein as“configured to,” “configurable to,” “operable/operative to,”“adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Thoseskilled in the art will recognize that “configured to,” “configurableto,” “operable/operative to,” “adapted/adaptable,” “able to,”“conformable/conformed to,” etc. can generally encompass active-statecomponents and/or inactive-state components and/or standby-statecomponents, unless context requires otherwise.

Illustrative Electromagntic Flow Regulator, Systems, and Methods

Given by way of overview and referring to FIG. 1A, an illustrativeelectromagnetic flow regulator 490 is provided for regulating flow of anelectrically conductive fluid. Magnetic conductors 510 are arranged infixed relative location, such as by being attached to a frame 491. Themagnetic conductors 510 define therealong a fluid flow path 141 for anelectrically conductive fluid through the electromagnetic flow regulator490. The magnetic conductors 510 define therethrough a fluid inlet pathfor the electrically conductive fluid that is substantially orthogonalto the fluid flow path 141. A field generation winding 570 that iscapable of carrying an electrical current is electromagneticallycouplable to the magnetic conductors 510 such that at least one magneticfield is generatable by the field generation winding 570 at the fluidinlet path.

In some embodiments the fluid inlet path may be defined by flow holes520 that are defined in the magnetic conductors 510. In addition, thefluid flow path 141 through the electromagnetic flow regulator 490 maybe defined inboard of the magnetic conductors 510.

The electromagnetic flow regulator 490 may be supplied with electricalpower from a power supply 590 via an electrical circuit 580 (and itscircuit segments 580 a, 580 b, and 580 c). In some embodiments the powersupply 590 may be controlled by a control unit 610. Illustrative detailsof the power supply 590 and the control unit will be set forth furtherbelow.

It will be appreciated that various embodiments of the electromagneticflow regulator 490 may be provided for various applications, as desired.Given by way of nonlimiting example, an illustrative electromagneticflow regulator 490 a, that may regulate flow of the electricallyconductive fluid by restricting flow of the electrically conductivefluid, will be discussed first. Another illustrative electromagneticflow regulator 490 b, that may regulate flow of the electricallyconductive fluid by restricting flow of the electrically conductivefluid and/or forcing flow of the electrically conductive fluid, willthen be discussed.

It will be appreciated that the electromagnetic flow regulators 490 aand 490 b may be used as desired for a particular application.Therefore, system-level applications and host environments will bedescribed herein with reference to the electromagnetic flow regulator490. Thus, references made herein to the electromagnetic flow regulator490 in the context of system-level applications and host environmentsalso encompass the electromagnetic flow regulator 490 a and theelectromagnetic flow regulator 490 b. That is, any reference made hereinto the electromagnetic flow regulator 490 in the context of system-levelapplications and host environments is also a reference to theelectromagnetic flow regulator 490 a or the electromagnetic flowregulator 490 b or both the electromagnetic flow regulator 490 a and theelectromagnetic flow regulator 490 b.

Still given by way of overview and still referring to FIG. 1A, thefollowing information is provided as a high-level introduction to someaspects of the electromagnetic flow regulator 490 a. As such, thefollowing information is provided in addition to the information setforth above for the electromagnetic flow regulator 490 (which need notbe repeated for an understanding). To that end, in various embodimentsof the electromagnetic flow regulator 490 a the field generation winding570 is disposed outboard of the magnetic conductors 510. In someembodiments the field generation winding 570 may include a helical coiland in some other embodiments the field generation winding 570 mayinclude substantially circular coils. In some embodiments magneticnonconductors 530 may be attached to the frame 491 and disposed betweenadjacent ones of the magnetic conductors 510. In such cases the fluidflow path 141 is further defined along the magnetic nonconductors 530.

An illustrative embodiment of the electromagnetic flow regulator 490 awill now be set forth by way of nonlimiting example. Referring now toFIG. 1B and given by way of overview, the magnetic conductors 510 arearranged in fixed relative location, such as by being attached to theframe 491. The magnetic conductors 510 define therealong the fluid flowpath 141 for the electrically conductive fluid through theelectromagnetic flow regulator 490 a. The magnetic conductors 510 definetherethrough the flow holes 520 that define the fluid inlet path for theelectrically conductive fluid that is substantially orthogonal to thefluid flow path 141. The field generation winding 570 that is capable ofcarrying an electrical current is disposed outboard of the magneticconductors 510. The field generation winding 570 is electromagneticallycouplable to the magnetic conductors 510 such that at least one magneticfield is generatable by the field generation winding 570 at the fluidinlet path.

Still referring to FIG. 1B and still by way of overview, in someembodiments the fluid flow path 141 through the electromagnetic flowregulator 490 a may be further defined inboard of the magneticconductors 510. In some embodiments magnetic nonconductors 530 may beattached to the frame 491 and disposed between adjacent ones of themagnetic conductors 510. In such cases, the fluid flow path 141 throughthe electromagnetic flow regulator 490 a may be further defined alongthe magnetic nonconductors 530, such as by being defined inboard of themagnetic nonconductors 530. In some embodiments the field generationwinding 570 may include a helical coil and in some other embodiments thefield generation winding 570 may include substantially circular coils.

Now that an overview has been given, the structure and operation of theelectromagnetic flow regulator 490 a—that can restrict the flow of theelectrically conductive fluid—will now be described.

Still referring to FIG. 1B, adjacent magnetic conductors 510 conduct amagnetic field 630 that is generated by an electrical current 600 thatflows through the field generation winding 570. The magnetic conductors510 may be made of cast iron, carbon steels, or specialty commercialalloys such as permalloys Deltamax and Sendust. In one embodiment, themagnetic conductors 510 may be upright, elongate, spaced-apart, andarranged in a generally cylindrical or tubular configuration formatingly disposing electromagnetic flow regulator 490 a into a device,system, host environment, or the like through which flow of theelectrically conductive fluid is to be regulated by the electromagneticflow regulator 490 a. Each magnetic conductor 510 may have a square,rectangular, parallelpiped, circular, or any other suitable transversecross-section.

Each of the adjacent magnetic conductors 510 defines one or more flowholes 520 for allowing flow of the electrically conductive fluid throughthe magnetic conductors 510. The magnetic conductor 510 is used toconcentrate the magnetic field potential within or in the vicinity ofthe conductive fluid flow path. It will be appreciated that the flowholes 520 are located at the portions 145 of the flow path 140. It willalso be appreciated that the flow path through the interior of theelectromagnetic flow regulator 490 a of the electrically conductivefluid is defined along the magnetic conductors 510—that is, inboard ofthe magnetic conductors 510. It will further be appreciated that theinlet flow path of the electrically conductive fluid through the flowholes 520 is substantially orthogonal to the flow path through theinterior of the electromagnetic flow regulator 490 a of the electricallyconductive fluid.

Interposed between adjacent ones of the magnetic conductors 510 arerespective ones of magnetic nonconductors 530. The magneticnonconductors 530 act to limit magnetic potential in areas outside theportions 145 of the electrically conductive fluid flow path 140. Properuse of magnetic conductors and non-conductors may help to maximize themagnetic field strength observed by the electrically conductive fluid inthe area of the conductive fluid at the portions 145 of the flow path140 for a given electrical current applied to the electromagnetic flowregulator 490 a. The magnetic nonconductors 530 may be made of Type 300stainless steel or the like. It will be appreciated that the flow paththrough the interior of the electromagnetic flow regulator 490 a of theelectrically conductive fluid is, therefore, also defined along themagnetic nonconductors 530—that is, inboard of the magneticnonconductors 530.

It will be appreciated that the selection of the number of flow holes520 involves consideration of the electrically conductive fluid'sfrictional flow resistance and the ability to provide a uniform magneticfield over the length and cross sectional flow area of the portions 145of the flow path 140. In some embodiments, multiple flow holes 520 havebeen chosen such that the magnetic field requirement is reduced and thefrictional loses are minimized.

Referring additionally to FIGS. 1C and 1D, the frame 491 includes a basemember 540 and a yoke 550. Upper and lower ends of the magneticconductors 510 and the magnetic nonconductors 530 are attached to theframe 491. The lower ends of the magnetic conductors 510 and themagnetic nonconductors 530 are attached to the base member 540.Attaching the lower ends of the magnetic conductors 510 and the magneticnonconductors 530 to the base member 540 fixes the lower ends of themagnetic conductors 510 and the magnetic nonconductors 530, such thatthe lower ends of the magnetic conductors 510 and the magneticnonconductors 530 cannot laterally move. Thus, the base member 540enhances vibrational and structural rigidity of the electromagnetic flowregulator 490 a as the electrically conductive fluid flows through theelectromagnetic flow regulator 490 a. More specifically, the lower endsof the magnetic conductors 510 and the magnetic nonconductors 530 may beattached to the base member 540 by a pair of location tabs 510 a and 510b. However, it will be appreciated that the lower ends of the magneticconductors 510 and the magnetic nonconductors 530 may be attached to thebase member 540 by welding or by any suitable means of attachment.

The disk-shaped yoke 550 fixes the upper ends of the magnetic conductors510 and the magnetic nonconductors 530, such that the upper ends of themagnetic conductors 510 and the magnetic nonconductors 530 cannotlaterally move. Thus, the yoke 550 enhances vibrational and structuralrigidity of the electromagnetic flow regulator 490 a as the relativelyhigh-velocity electrically conductive fluid flows through theelectromagnetic flow regulator 490 a. The yoke 550 includes a firstportion 550 a and a second portion 550 b. The second portion 550 b isarranged inwardly concentrically with respect to the first portion 550a. The upper ends of the magnetic conductors 510 and the magneticnonconductors 530 are suitably attached to the second portion 550 b,such as by a pair of location tabs 550 c and 550 d. However, it will beappreciated that the upper ends of the magnetic conductors 510 and themagnetic nonconductors 530 may be attached to the second portion 550 bof the yoke 550 by welding or by any suitable means of attachment

In some embodiments the yoke 550 may have a recess 555 for matingengagement of the electromagnetic flow regulator 490 a with the device,system, host environment, or the like, through which flow is to beregulated (indicated generally at 30). Interposed between the firstportion 550 a and the second portion 550 b is an annular insulatorportion 560 for isolating the electromagnetic circuit from the device,system, host environment, or the like 30 through which flow is to beregulated. The insulator portion 560 is a dielectric (i.e., electricallynonconducting substance) and may be made from any suitable material forresisting flow of an electric current. In this regard, the insulatorportion 560 may be made of porcelain, glass, plastic (e.g., Bakelite),rubber, acrylic, polyurethane, or the like. Another purpose of the basemember 540 and the yoke 550, when made from a magnetic material, is toprovide magnetic containment at the top and bottom of theelectromagnetic flow regulator 490 a.

Referring now to FIGS. 1B and 1C, in some embodiments the fieldgeneration winding 570 (sometimes referred to as an induction coil) mayhelically surround the tubular configuration of the magnetic conductors510 and the magnetic nonconductors 530. In such cases the helicalinduction coil 570 extends spirally along the tubular configurationdefined by the magnetic conductors 510 and the magnetic nonconductors530. In some other embodiments, the induction coil 570 need nothelically surround the tubular configuration defined by the magneticconductors 510 and the magnetic nonconductors 530. For example, in someother embodiments the induction coil 570 may include separate,spaced-apart induction coils 570. In such cases, each induction coil 570encircles the tubular configuration of the magnetic conductors 510 andthe magnetic nonconductors 530.

Regardless of form of the field generation winding 570, the inductioncoils 570 are coupled to the magnetic conductors 510 and are interposedbetween and near respective ones of the flow holes 520. A purpose of theinduction coils 570 is to generate magnetic fields at or near respectiveones of the flow holes 520. The induction coils 570 may be made from anysuitable electrically conductive material such as copper, silver,aluminum, or the like.

Moreover, the induction coils 570 may include adjacent current-carryinglaminations or layers. Referring additionally to FIG. 1E, thelaminations include a conductor layer 575 a and an adjacent insulatorlayer 575 b arranged side-by-side in an alternating fashion. The numberof turns or layers in the current-carrying layers reduces the electricalcurrent required to produce a magnetic field of a given strength.

Referring to FIG. 1B, the electromagnetic flow regulator 490 a may beelectrically coupled to an electrical circuit 580 that defines a circuitsegment 580 a having a first end thereof connected to the induction coil570 and a second end thereof connected to a circuit segment 580 b. Inaddition, the circuit 580 has a circuit segment 580 c having a first endthereof connected to the circuit segment 580 b and a second end thereofconnected to the base member 540. In one embodiment, a power supply 590is electrically connected to the electrical circuit 580 for supplying anelectrical current to the induction coils 570. In this embodiment, theelectrical current flows in the direction of directional arrows 600. Thepower supply 590 may be a direct current output power supply withvariable output voltage. Such a commercially available power supply thatmay be suitable for this purpose may be available from Colutron ResearchCorporation located in Boulder, Colo. U.S.A.

A control unit 610 may be electrically connected to the power supply 590for controlling and regulating the electric current supplied by thepower supply 590. The magnitude of the magnetic force acting on theelectrically conductive fluid is directly proportional to the outputvoltage of the power supply 590, such that varying the output voltagevaries the magnitude of the force and flow rate of the electricallyconductive fluid. In other words, increasing the output voltageincreases the magnetic field and force acting on the electricallyconductive fluid and decreasing the output voltage decreases themagnetic field and force acting on the electrically conductive fluid.

Referring now to FIG. 1F, an induced electric field “E” will affect orresist an established flow of electrically conductive fluid into theelectromagnetic flow regulator 490 a. The movement of an electricallyconductive fluid through a magnetic field results in the inducedelectric field according to the equation:

E=v×B,   Equation (1)

where,

-   -   B is the magnetic field vector (e.g., in Tesla);    -   E is the induced electric field vector (e.g., in volts per        meter);    -   v is the velocity of the electrically conductive fluid (e.g., in        meters per second);

Because of the electrical conductivity of the fluid, the electric fieldE causes a current density J in the fluid. The current J then produces aLorentz force density f, and resultant total force F, that opposes theflow of the electrically conductive fluid as shown in the expressions:

f=J×B(the Lorentz Force Law)   Equation (2)

and

F=f×volume Equation (3)

Referring additionally to FIGS. 1G, 1H, 1I, and 1J, the electric currentsupplied from the power supply 590 and the electrical circuit 580 to theinduction coils 570 flows along the induction coils 570 generally in thedirection illustrated by the directional arrows 600. In this case, themagnetic field B will act generally in the direction illustrated by thedirectional arrow 630. The magnetic field B that is indicated by thearrow 630 acts substantially perpendicularly to the flow of theelectrically conductive fluid through the portion 145 of the fluid flowpath 140. The generated Lorentz force F will act in the direction of thedirectional arrow 640 substantially perpendicularly to the magneticfield B indicated by the arrow 630. The terminology “substantiallyperpendicularly” is defined herein to mean an orientation that is within±45° of being precisely perpendicular. It will be appreciated that theinduced vectors are maximized or minimized when placed in perpendiculararrangements. It will also be understood that practical applications maynot allow perpendicular orientation. However, such orientations maystill result in sufficient vector magnitudes to perform the functiondescribed herein. The Lorentz force F acting in the direction of thearrow 640 will resist or otherwise oppose flow of the electricallyconductive fluid as the electrically conductive fluid attempts to movethrough the flow holes 520. In other words, the force F applies abraking force to the electrically conductive fluid.

Given by way of another nonlimiting example, another illustrativeelectromagnetic flow regulator 490 b may regulate flow of theelectrically conductive fluid by restricting flow of the electricallyconductive fluid and/or forcing flow of the electrically conductivefluid.

Given by way of overview and referring back to FIG. 1A, the followinginformation is provided as a high-level introduction to some aspects ofthe electromagnetic flow regulator 490 b. As such, the followinginformation is provided in addition to the information set forth abovefor the electromagnetic flow regulator 490 (which need not be repeatedfor an understanding). To that end, in various embodiments of theelectromagnetic flow regulator 490 b the field generation winding 570includes conductors 910 a (not shown in FIG. 1A for purposes of clarity)that are capable of carrying electrical current and that that aredisposed inboard of the magnetic conductors and conductors 910 b thatare capable of carrying electrical current and that are disposedoutboard of the magnetic conductors. The electromagnetic flow regulator490 b may include magnetic nonconductors (not shown in FIG. 1A forpurposes of clarity) that are attached to the frame and disposed betweenadjacent ones of the magnetic conductors. In such cases, the fluid flowpath is further defined along the magnetic nonconductors, and the fluidinlet path is further defined through the magnetic nonconductors.

An illustrative embodiment of the electromagnetic flow regulator 490 bwill now be set forth by way of nonlimiting example. Referring now toFIGS. 1K, 1L, 1M, and 1N and given by way of overview, magneticconductors 510, 890 are arranged in fixed relative location, such as bybeing attached to a frame 491. The magnetic conductors 510, 890 definetherealong a fluid flow path for an electrically conductive fluid anddefine therethrough flow holes 520 b that define a fluid inlet path forthe electrically conductive fluid that is substantially orthogonal tothe fluid flow path. A field generation winding 910 a, 910 b includesconductors 910 a that are capable of carrying electrical current andthat are disposed inboard of the magnetic conductors 510, 890 andconductors 910 b that are capable of carrying electrical current andthat are disposed outboard of the magnetic conductors 510, 890. Thefield generation winding 910 a, 910 b is electromagnetically couplableto the magnetic conductors 510, 890 such that at least one magneticfield is generatable by the field generation winding 910 a, 910 b at thefluid inlet path. Illustrative details will be set forth below.

The frame 491 includes a casing 875 that is attached at its lower end tothe base member 540 and that is attached at its upper end to the yoke550. The casing includes regions 880 of low magnetic susceptibility(that is, the magnetic nonconductors 530) and regions 890 of highmagnetic susceptibility (that is, the magnetic conductors 510) asdescribed below.

Flow holes 520 b may be defined vertically and circumferentially aroundthe casing 875 as follows. Each flow 520 b is formed through a region880 of low magnetic susceptibility material capable of conducting anelectrical current—that is, a magnetic nonconductor 530—and through aregion 890 of high magnetic susceptibility material—that is, a magneticconductor 510—that are disposed on opposite sides of the flow hole 520b.

Interposed between the regions 880 and 890 are respective ones ofinsulation segments 900. Thus, the regions 880 and 890 and theinsulation segments 900 are in communication with the flow hole 520 b.

A field generation winding is composed of current-carrying wires 910 aand 910 b. The current-carrying wire 910 a extends longitudinally alongthe interior of the casing 875. The current-carrying wire 910 b isintegrally connected to the current-carrying wire 910 a and extendslongitudinally along the exterior of the casing 875. A circuit segment580 a of an electrical circuit 580 is electrically connected to thecurrent-carrying wire 910 a and a circuit segment 580 c of theelectrical circuit 580 is electrically connected to the current-carryingwire 910 b. This configuration results in a magnetic field B that ishorizontal and the current-carrying wires 910 a and 910 b that arevertical. An electric field E is established in the vertical directionacross the flow holes 520 b.

A thin lamination or insulating layer 895 may be placed on thecircumferential interior and exterior surfaces of the low magneticsusceptibility material 880 and high magnetic susceptibility material890 to help prevent leakage of electrical current to material or areassurrounding the flow regulator 490 b.

The current I, or the electric field E, can be reversed to either forceor restrict movement of the electrically conductive fluid through theflow holes 520 b. The current-carrying wire 910 a (disposed on theinterior of the casing 875) produces a downwardly flowing current andthe current-carrying wire 910 b (disposed on the exterior of the casing875) produces an upwardly flowing current. Such an arrangement of thecurrent-carrying wires 910 a and 910 b make a continuous magnetic fieldB that does not block the flow holes 520 b.

While the current density J in Equation (2) is generated in a directionthat opposes the flow of conducting fluid in the absence of an externaldriving force (such as in the flow regulator 490 a), the application ofan external driving force in the flow regulator 490 b can increase ordecrease J in either direction. The resultant force density f inEquation (2), and hence likewise the resultant force F, can then bedriven to a direction that either aids or opposes the flow.

It will be appreciated that orientation of the electromagnetic flowregulators 490 a and 490 b (and their components) may be vertical (asdescribed and shown herein) or horizontal, as determined by a particularapplication. Thus, the terms “horizontal” and “vertical” are used aboveonly to explain the nonlimiting illustrative examples presented herein.In some applications, the orientation of the electromagnetic flowregulator 490 a and/or 490 b may be orthogonal to the nonlimitingorientation described and illustrated herein. Therefore, it will beappreciated that the terms “horizontal” and “vertical” may beinterchanged with each other, as determined by orientations entailed inparticular applications.

Referring back to FIG. 1A, it will be appreciated that a system forelectromagnetically regulating flow of an electrically conductive fluidmay include a source of electrical power, such as the power supply 590,and the electromagnetic flow regulator 490. Another system forelectromagnetically regulating flow of an electrically conductive fluidmay include a source of electrical power, such as the power supply 590,and the electromagnetic flow regulator 490 a. Similarly, another systemfor electromagnetically regulating flow of an electrically conductivefluid may include a source of electrical power, such as the power supply590, and the electromagnetic flow regulator 490 b. Any of the abovesystems may also include a controller, such as the control unit 610, ifdesired. The power supply 590, the control unit 610, and theelectromagnetic flow regulators 490, 490 a, and 490 b have beendiscussed above. Details of their construction and operation need not berepeated for an understanding.

Now that illustrative details have been set forth above regardingconstruction and operation of the electromagnetic flow regulators 490,490 a, and 490 b, various methods for electromagnetically regulatingflow of an electrically conductive fluid will be set forth.

Referring now to FIG. 2A, an illustrative method 2000 is provided forregulating flow of an electrically conductive fluid. The method 2000starts at a block 2002. At a block 2004 an electrically conductive fluidis flowed through a fluid inlet path that is defined through a pluralityof magnetic conductors of an electromagnetic flow regulator. At a block2006 a Lorentz force that regulates flow of the electrically conductivefluid through the fluid inlet path is generated. At a block 2008 theelectrically conductive fluid is flowed along a fluid flow path definedalong the plurality of magnetic conductors and that is substantiallyorthogonal to the fluid inlet path. The method 2000 stops at a block2010.

Referring additionally to FIG. 2B, in an embodiment generating a Lorentzforce that regulates flow of the electrically conductive fluid throughthe fluid inlet path at the block 2006 may include generating a Lorentzforce that resists flow of the electrically conductive fluid through thefluid inlet path at a block 2012. For example and referring additionallyto FIG. 2C, generating a Lorentz force that resists flow of theelectrically conductive fluid through the fluid inlet path at the block2012 may include generating at least one magnetic field at the fluidinlet path by an electrical current-carrying field generation windingdisposed outboard of the plurality of magnetic conductors at a block2014.

Referring now to FIGS. 2A and 2D, in another embodiment generating aLorentz force that regulates flow of the electrically conductive fluidthrough the fluid inlet path at the block 2006 may include generating aLorentz force that forces flow of the electrically conductive fluidthrough the fluid inlet path at a block 2016. For example, and referringadditionally to FIG. 2E, generating a Lorentz force that forces flow ofthe electrically conductive fluid through the fluid inlet path at theblock 2016 may include generating at least one magnetic field at thefluid inlet path by a first plurality of electrical current-carryingconductors that are disposed inboard of the plurality of magneticconductors and a second plurality of electrical current-carryingconductors that are disposed outboard of the plurality of magneticconductors at a block 2018.

Referring now to FIG. 2F, an illustrative method 2100 is provided forregulating flow of an electrically conductive fluid. It will beappreciated that the method 2100 regulates flow of an electricallyconductive fluid by restricting flow of the electrically conductivefluid.

The method 2100 starts at a block 2102. At a block 2104 an electricallyconductive fluid is flowed through a plurality of flow holes definedthrough a plurality of magnetic conductors in an electromagnetic flowregulator. At a block 2106 a Lorentz force that resists flow of theelectrically conductive fluid through the plurality of flow holes isgenerated. At a block 2108 the electrically conductive fluid is flowedalong a fluid flow path defined along the plurality of magneticconductors and that is substantially orthogonal to flow of theelectrically conductive fluid through the plurality of flow holes. Themethod 2100 stops at a block 2110.

Referring additionally to FIG. 2G, generating a Lorentz force thatresists flow of the electrically conductive fluid through the pluralityof flow holes at the block 2106 may include generating at least onemagnetic field at the plurality of flow holes by an electricalcurrent-carrying field generation winding disposed outboard of theplurality of magnetic conductors at a block 2112.

Referring now to FIG. 2H, an illustrative method 2200 is provided forregulating flow of an electrically conductive fluid. It will beappreciated that the method 2200 regulates flow of an electricallyconductive fluid by forcing flow of the electrically conductive fluid.

The method 2200 starts at a block 2202. At a block 2204 an electricallyconductive fluid is flowed through a plurality of flow holes definedthrough a plurality of magnetic conductors. At a block 2206 a Lorentzforce that forces flow of the electrically conductive fluid through theplurality of flow holes is generated. At a block 2208 the electricallyconductive fluid is flowed along a fluid flow path defined along theplurality of magnetic conductors and that is substantially orthogonal toflow of the electrically conductive fluid through the plurality of flowholes. The method 2200 stops at a block 2210.

Referring additionally to FIG. 2I, generating a Lorentz force thatforces flow of the electrically conductive fluid through the pluralityof flow holes at the block 2206 may include generating at least onemagnetic field at the plurality of flow holes by a first plurality ofelectrical current-carrying conductors that are disposed inboard of theplurality of magnetic conductors and a second plurality of electricalcurrent-carrying conductors that are disposed outboard of the pluralityof magnetic conductors at a block 2212.

Referring now to FIG. 3A, an illustrative method 3000 is provided forfabricating an electromagnetic flow regulator for regulating flow of anelectrically conductive fluid. The method 3000 starts at a block 3002.At a block 3004 a fluid inlet path for an electrically conductive fluidis defined through a plurality of magnetic conductors. At a block 3006the plurality of magnetic conductors is attached to a frame such that afluid flow path for the electrically conductive fluid is defined alongthe plurality of magnetic conductors substantially orthogonal to thefluid inlet path. At a block 3008 a field generation winding capable ofcarrying an electrical current is disposed, the field generation windingbeing electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by thefield generation winding at the fluid inlet path.

Referring additionally to FIG. 3B, attaching the plurality of magneticconductors to a frame such that a fluid flow path for the electricallyconductive fluid is defined along the plurality of magnetic conductorssubstantially orthogonal to the fluid inlet path at the block 3006 mayinclude attaching the plurality of magnetic conductors to a frame suchthat a fluid flow path for the electrically conductive fluid is definedinboard of the plurality of magnetic conductors and along the pluralityof magnetic conductors substantially orthogonal to the fluid inlet pathat a block 3012.

Referring now to FIGS. 3A and 3C, in some embodiments disposing a fieldgeneration winding capable of carrying an electrical current, the fieldgeneration winding being electromagnetically couplable to the pluralityof magnetic conductors such that at least one magnetic field isgeneratable by the field generation winding at the fluid inlet path atthe block 3008 may include disposing outboard of the plurality ofmagnetic conductors a field generation winding capable of carrying anelectrical current, the field generation winding beingelectromagnetically couplable to the plurality of magnetic conductorssuch that at least one magnetic field is generatable by the fieldgeneration winding at the fluid inlet path at a block 3014. It will beappreciated that the block 3014 is performed to fabricate embodiments ofan electromagnetic flow regulator that may regulate flow of anelectrically conductive fluid by restricting flow of the electricallyconductive fluid.

For example and referring to FIG. 3D, in some embodiments disposingoutboard of the plurality of magnetic conductors a field generationwinding capable of carrying an electrical current, the field generationwinding being electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by thefield generation winding at the fluid inlet path at the block 3014 mayinclude disposing a helical coil outboard of the plurality of magneticconductors a field generation winding capable of carrying an electricalcurrent, the field generation winding being electromagneticallycouplable to the plurality of magnetic conductors such that at least onemagnetic field is generatable by the field generation winding at thefluid inlet path at a block 3016.

As another example and referring now to FIG. 3E, in some otherembodiments disposing outboard of the plurality of magnetic conductors afield generation winding capable of carrying an electrical current, thefield generation winding being electromagnetically couplable to theplurality of magnetic conductors such that at least one magnetic fieldis generatable by the field generation winding at the fluid inlet pathat the block 3014 may include disposing a plurality of substantiallycircular coils outboard of the plurality of magnetic conductors a fieldgeneration winding capable of carrying an electrical current, the fieldgeneration winding being electromagnetically couplable to the pluralityof magnetic conductors such that at least one magnetic field isgeneratable by the field generation winding at the fluid inlet path at ablock 3018.

Referring now to FIGS. 3A and 3F, in some embodiments at a block 3020 aplurality of magnetic nonconductors may be attached to the frame suchthat ones of the plurality of magnetic nonconductors are disposedbetween adjacent ones of the plurality of magnetic conductors. Referringadditionally to FIG. 3G, in some embodiments attaching a plurality ofmagnetic nonconductors to the frame such that ones of the plurality ofmagnetic nonconductors are disposed between adjacent ones of theplurality of magnetic conductors at the block 3020 may include attachinga plurality of magnetic nonconductors to the frame such that ones of theplurality of magnetic nonconductors are disposed between adjacent onesof the plurality of magnetic conductors and such that the fluid flowpath is further defined along the plurality of magnetic nonconductors ata block 3022.

Referring now to FIGS. 3A and 3H, in some embodiments disposing a fieldgeneration winding capable of carrying an electrical current, the fieldgeneration winding being electromagnetically couplable to the pluralityof magnetic conductors such that at least one magnetic field isgeneratable by the field generation winding at the fluid inlet path atthe block 3008 may include disposing a first plurality of electricalconductors inboard of the plurality of magnetic conductors and a secondplurality of electrical conductors outboard of the plurality of magneticconductors, the first and second plurality of conductors beingelectromagnetically couplable to the plurality of magnetic conductorssuch that at least one magnetic field is generatable by the first andsecond pluralities of conductors at the fluid inlet path at a block3024. It will be appreciated that the block 3024 is performed tofabricate embodiments of an electromagnetic flow regulator that mayregulate flow of an electrically conductive fluid by restricting flow ofthe electrically conductive fluid.

Referring additionally to FIG. 31, in some embodiments at a block 3026 aplurality of magnetic nonconductors may be attached to the frame suchthat ones of the plurality of magnetic nonconductors are disposedbetween adjacent ones of the plurality of magnetic conductors. Forexample, referring additionally to FIG. 3J in some embodiments attachinga plurality of magnetic nonconductors to the frame such that ones of theplurality of magnetic nonconductors are disposed between adjacent onesof the plurality of magnetic conductors at the block 3026 may includeattaching a plurality of magnetic nonconductors to the frame such thatones of the plurality of magnetic nonconductors are disposed betweenadjacent ones of the plurality of magnetic conductors and such that thefluid flow path is further defined along the plurality of magneticnonconductors at a block 3028. Referring additionally to FIG. 3K, at ablock 3030 the fluid inlet path may be further defined through theplurality of magnetic nonconductors.

Referring now to FIG. 3L, a method 3100 is provided for fabricating anelectromagnetic flow regulator for regulating flow of an electricallyconductive fluid. It will be appreciated that the method 3100 isperformed to fabricate embodiments of an electromagnetic flow regulatorthat may regulate flow of an electrically conductive fluid byrestricting flow of the electrically conductive fluid.

The method 3100 starts at a block 3102. At a block 3104 a plurality offlow holes that defines a fluid inlet path for an electricallyconductive fluid is defined through a plurality of magnetic conductors.At a block 3106 the plurality of magnetic conductors is attached to aframe such that a fluid flow path for the electrically conductive fluidis defined along the plurality of magnetic conductors substantiallyorthogonal to the fluid inlet path. At a block 3108 a field generationwinding capable of carrying an electrical current is disposed outboardof the plurality of magnetic conductors, the field generation windingbeing electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by thefield generation winding at the plurality of flow holes. The method 3100stops at a block 3110.

Referring additionally to FIG. 3M, attaching the plurality of magneticconductors to a frame such that a fluid flow path for the electricallyconductive fluid is defined along the plurality of magnetic conductorssubstantially orthogonal to the fluid inlet path at the block 3106 mayinclude attaching the plurality of magnetic conductors to a frame suchthat a fluid flow path for the electrically conductive fluid is definedinboard of the plurality of magnetic conductors and along the pluralityof magnetic conductors substantially orthogonal to the fluid inlet pathat a block 3112.

Referring to FIGS. 3L and 3N, at a block 3114 a plurality of magneticnonconductors may be attached to the frame such that ones of theplurality of magnetic nonconductors are disposed between adjacent onesof the plurality of magnetic conductors.

Referring to FIGS. 3L and 3O, in some embodiments disposing outboard ofthe plurality of magnetic conductors a field generation winding capableof carrying an electrical current, the field generation winding beingelectromagnetically couplable to the plurality of magnetic conductorssuch that at least one magnetic field is generatable by the fieldgeneration winding at the plurality of flow holes at the block 3108 mayinclude disposing outboard of the plurality of magnetic conductors ahelical coil capable of carrying an electrical current, the helical coilbeing electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by thehelical coil at the plurality of flow holes at a block 3116.

Referring to FIGS. 3L and 3P, in some other embodiments disposingoutboard of the plurality of magnetic conductors a field generationwinding capable of carrying an electrical current, the field generationwinding being electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by thefield generation winding at the plurality of flow holes at the block3108 may include disposing outboard of the plurality of magneticconductors a plurality of substantially circular coils capable ofcarrying an electrical current, the plurality of substantially circularcoils being electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by theplurality of substantially circular coils at the plurality of flow holesat a block 3118.

Referring now to FIG. 3Q, a method 3200 is provided for fabricating anelectromagnetic flow regulator for regulating flow of an electricallyconductive fluid. It will be appreciated that the method 3200 isperformed to fabricate embodiments of an electromagnetic flow regulatorthat may regulate flow of an electrically conductive fluid by forcingflow of the electrically conductive fluid.

The method 3200 starts at a block 3202. At a block 3204 a plurality offlow holes that defines a fluid inlet path for an electricallyconductive fluid is defined through a plurality of magnetic conductors.At a block 3206 the plurality of magnetic conductors is attached to aframe such that a fluid flow path for the electrically conductive fluidis defined along the plurality of magnetic conductors substantiallyorthogonal to the fluid inlet path. At a block 3208 a first plurality ofelectrical conductors is disposed inboard of the plurality of magneticconductors and a second plurality of electrical conductors is disposedoutboard of the plurality of magnetic conductors, the first and secondplurality of conductors being electromagnetically couplable to theplurality of magnetic conductors such that at least one magnetic fieldis generatable by the first and second pluralities of conductors at theplurality of flow holes. The method 3200 stops at a block 3210.

Referring additionally to FIG. 3R, in some embodiments a plurality ofmagnetic nonconductors may be attached to the frame such that ones ofthe plurality of magnetic nonconductors are disposed between adjacentones of the plurality of magnetic conductors at a block 3212. Forexample and referring additionally to FIG. 3S, attaching a plurality ofmagnetic nonconductors to the frame such that ones of the plurality ofmagnetic nonconductors are disposed between adjacent ones of theplurality of magnetic conductors at the block 3212 may include attachinga plurality of magnetic nonconductors to the frame such that ones of theplurality of magnetic nonconductors are disposed between adjacent onesof the plurality of magnetic conductors and such that the fluid flowpath is further defined along the plurality of magnetic nonconductors ata block 3214.

Referring additionally to FIG. 3T, the plurality of flow holes may befurther defined through the plurality of magnetic nonconductors at ablock 3216.

Illustrative Host Environments

It will be appreciated that embodiments of the electromagnetic flowregulator 490 may be used in any host environment in which it is desiredto electromagnetically regulate flow of an electrically conductivefluid. Given by way of example only and not of limitation, embodimentsof the electromagnetic flow regulator 490 may be used to: regulate flowof a molten metal (e.g., zinc, lead, aluminum, iron and magnesium in theprimary metals industries; rapidly start and stop a shot of molten metalinto a mold for casting; regulate the flow of a liquid metal coolant toa computer chip; modulate the rate of release of molten filler wireduring electric arc Welding; and the like.

Given by way of another nonlimiting example, embodiments of theelectromagnetic flow regulator 490 may be used in a nuclear fissionreactor to regulate flow of an electrically conductive reactor coolant.Illustrative examples related to electromagnetically regulating flow ofan electrically conductive reactor coolant in a nuclear fission reactorwill be discussed below.

It will be appreciated that, as discussed above, embodiments of theelectromagnetic flow regulator 490 may be used in any host environmentin which it is desired to electromagnetically regulate flow of anelectrically conductive fluid. In the interest of brevity, discussionsof host environments will be limited to that of a nuclear fissionreactor. However, no limitation of applicable host environments to thatof a nuclear fission reactor is intended and should not be inferred.

Reference is made in the following discussion to the electromagneticflow regulator 490 and the drawings illustrate the electromagnetic flowregulator 490. It will be appreciated that such references andillustrations of the electromagnetic flow regulator 490 are intended toinclude the electromagnetic flow regulators 490 a and 490 b. However, inthe interest of brevity, references and illustrations are made onlyregarding the electromagnetic flow regulator 490.

Illustrative Nuclear Fission Reactor, Systems, and Methods

Illustrative nuclear fission reactors, systems for regulating flow of anelectrically conductive reactor coolant, and methods of regulating flowof an electrically conductive reactor coolant in a nuclear fissionreactor will now be discussed below by way of nonlimiting examples. Theexamples will be discussed below by way of illustration only and not oflimitation.

It may be desired to regulate flow of electrically conductive reactorcoolant in a nuclear fission reactor with one or more of theelectromagnetic flow regulators 490. As is known, heat is produced in anuclear fission reactor when neutrons are liberated by fissile nuclides.This phenomenon is used in a commercial nuclear fission reactor toproduce continuous heat that, in turn, is used to generate electricity.

However, possibility of heat damage to some reactor structural materialsmay be increased due to “peak” temperature (i.e., hot channel peakingfactor) which, in turn, occurs due to uneven neutron flux distributionin the reactor core. This peak temperature is, in turn, due toheterogeneous control rod/fuel rod distribution. Heat damage may occurif the peak temperature exceeds material limits.

In addition, reactors operating in the fast neutron spectrum may bedesigned to have a fertile fuel “breeding blanket” material present atthe core periphery. Such reactors will tend to breed fuel into thebreeding blanket material through neutron absorption. This results in anincreasing power output in the reactor periphery as the reactorapproaches the end of a fuel cycle.

Flow of coolant through the peripheral assemblies at the beginning of areactor fuel cycle can be established to maintain a safe operatingtemperature and compensate for the increase in power which will occur asburn-up increases during the fuel cycle. Typically, this requires thatexcess coolant pumping power be used at the beginning of a fuel cyclethan is needed.

Additionally, in the case of a traveling wave nuclear fission reactor,the heat generation rate of a nuclear fission module (or assembly) maychange with respect to proximity of the nuclear fission module to anuclear fission deflagration wave associated with operating thetraveling wave nuclear fission reactor.

A reactivity change (i.e., change in the responsiveness of the reactor)may be produced because of fuel burnup. Burnup is typically defined asthe amount of energy generated per unit mass of fuel and is usuallyexpressed in units of megawatt-days per metric tonne of heavy metal(MWd/MTHM) or gigawatt-days per metric tonne of heavy metal (GWd/MTHM).More specifically, reactivity change is related to the relative abilityof the reactor to produce more or less neutrons than the exact amountneeded to sustain a critical chain reaction. Responsiveness of a reactoris typically characterized as the time derivative of a reactivity changecausing the reactor to increase or decrease in power exponentially wherethe time constant is known as the reactor period.

In this regard, control rods made of neutron absorbing material aretypically used to adjust and control the changing reactivity. Suchcontrol rods are reciprocated in and out of the reactor core to variablycontrol neutron absorption and thus the neutron flux level andreactivity in the reactor core. The neutron flux level is depressed inthe vicinity of the control rod and potentially higher in areas remotefrom the control rod. Thus, the neutron flux is not uniform across thereactor core. This results in higher fuel burnup in those areas ofhigher neutron flux.

It will be appreciated that neutron flux and power density variationsare due to many factors. Proximity to a control rod may or may not bethe primary factor. For example, the neutron flux typically dropssignificantly at core boundaries when no nearby control rod is present.This effect, in turn, may cause overheating or peak temperatures inthose areas of higher neutron flux. Such peak temperatures mayundesirably reduce the operational life of structures subjected to suchpeak temperatures by altering the mechanical properties of thestructures. Also, reactor power density, which is proportional to theproduct of the neutron flux and the fission macroscopic cross-section,may be limited by the ability of core structural materials to withstandsuch peak temperatures without damage.

Regulating flow of reactor coolant into individual nuclear fission fuelassemblies (sometimes referred to herein as nuclear fission modules) canhelp tailor flow of reactor coolant as desired to help achieve a moreuniform temperature profile and/or power density profile across thereactor core. A more uniform temperature profile or power densityprofile across the reactor core can help lessen the possibility of heatdamage to some reactor structural materials. In cases when the reactorcoolant is an electrically conductive fluid, the electromagnetic flowregulator 490 may be used to help regulate flow of the electricallyconductive reactor coolant. Some illustrative details will be discussedbelow by way of illustration only and not of limitation.

Referring now to FIG. 4A by way of example only and not by way oflimitation, a nuclear fission reactor system 10includes an electricallyconductive reactor coolant. The nuclear fission reactor system 10includes at least one electromagnetic flow regulator 490 (not shown inFIG. 4A for purposes of clarity) to help regulate flow of theelectrically conductive reactor coolant. As described more fullyhereinbelow, the nuclear fission reactor system 10 may be a “travelingwave” nuclear fission reactor system.

Given by way of brief overview, in some embodiments the reactor system10 generates electricity that is transmitted over transmission lines(not shown) to users of the electricity. In some other embodiments thereactor system 10 may be used to conduct tests, such as tests todetermine effects of temperature on reactor materials.

Referring to FIGS. 4A and 4B, the reactor system 10 includes a nuclearfission reactor core 20 that includes nuclear fission fuel assembliesor, as also referred to herein, nuclear fission modules 30. The nuclearfission reactor core 20 is sealingly housed within a reactor coreenclosure 40. By way of example only and not by way of limitation, eachnuclear fission module 30 may form a hexagonally shaped structure intransverse cross-section, as shown, so that more nuclear fission modules30 may be closely packed together within the reactor core 20 (ascompared to other shapes for the nuclear fission module 30, such ascylindrical or spherical shapes). Each nuclear fission module 30includes fuel rods 50 for generating heat due to the nuclear fissionchain reaction process.

The fuel rods 50 may be surrounded by a fuel rod canister 60, ifdesired, for adding structural rigidity to the nuclear fission modules30 and for segregating the nuclear fission modules 30 one from anotherthe when nuclear fission modules 30 are disposed in the nuclear fissionreactor core 20. Segregating the nuclear fission modules 30 one fromanother avoids transverse coolant cross flow between adjacent nuclearfission modules 30. Avoiding transverse coolant cross flow preventstransverse vibration of the nuclear fission modules 30. Such transversevibration might otherwise increase risk of damage to the fuel rods 50.

In addition, segregating the nuclear fission modules 30 one from anotherallows control of coolant flow on an individual module-by-module basis,as described more fully hereinbelow. Controlling coolant flow toindividual nuclear fission modules 30 efficiently manages coolant flowwithin the reactor core 20, such as by directing coolant flowsubstantially according to the non-uniform temperature distribution inthe reactor core 20. In other words, more coolant may be directed tothose nuclear fission modules 30 having higher temperature.

In some illustrative embodiments and given by way of illustration andnot of limitation, the coolant may have an average nominal volumetricflow rate of approximately 5.5 m³/sec (i.e., approximately 194 cubicft³/sec) and an average nominal velocity of approximately 2.3 msec(i.e., approximately 7.55 ft/sec) in the case of an illustrative sodiumcooled reactor during normal operation. The fuel rods 50 are adjacentone to another and define a coolant flow channel 80 (see FIG. 4C)therebetween for allowing flow of coolant along the exterior of the fuelrods 50. The canister 60 may include means (not shown) for supportingand for tying the fuel rods 50 together. Thus, the fuel rods 50 arebundled together within the canister 60 so as to form the hexagonalnuclear fission modules 30. Although the fuel rods 50 are adjacent toeach other, the fuel rods 50 are maintained in a spaced-apartrelationship by a wire wrapper 90 (see FIG. 5B) that surrounds andextends spirally along the length of each fuel rod 50 in a serpentinefashion.

The fuel rods 50 include nuclear fuel material. Some of the fuel rods 50include a fissile nuclide, such as without limitation uranium-235,uranium-233, or plutonium-239. Some of the fuel rods 50 may include afertile nuclide, such as without limitation thorium-232 and/oruranium-238, which may be transmuted via neutron capture during thefission process into fissile nuclides. In some embodiments some of thefuel rods 50 may include a predetermined mixture of fissile and fertilenuclides.

Referring back to FIG. 4A, the reactor core 20 is disposed within areactor pressure vessel 120 for preventing leakage of radioactivematerials, gasses or liquids from the reactor core 20 to the surroundingbiosphere. The pressure vessel 120 may be made of steel or othermaterial of suitable size and thickness to reduce risk of such radiationleakage and to support required pressure loads. In addition, in someembodiments a containment vessel (not shown) may sealingly surroundparts of the reactor system 10 for further reducing possibility ofleakage of radioactive particles, gasses or liquids from the reactorcore 20 to the surrounding biosphere.

A primary loop coolant pipe 130 is coupled to the reactor core 20 forallowing a suitable coolant to flow through the reactor core 20 in orderto cool the reactor core 20. The primary loop coolant pipe 130 may bemade from any suitable material, such as stainless steel. It will beappreciated that, if desired, the primary coolant loop pipe 130 may bemade not only from ferrous alloys, but also from non-ferrous alloys,zirconium-based alloys or other suitable structural materials orcomposites

As discussed above, the coolant carried by primary loop coolant pipe 130is an electrically conductive fluid, which is defined herein to mean anyfluid that facilitates the passage of electrical current. For example,in some embodiments the electrically conductive fluid may be a liquidmetal such as without limitation sodium, potassium, lithium, lead andmixtures thereof. For example, in an illustrative embodiment the coolantmay suitably be a liquid sodium (Na) metal or sodium metal mixture, suchas sodium-potassium (Na—K). In some other embodiments the coolant may bea metal alloy, such as lead-bismuth (Pb—Bi). In some other embodimentsthe electrically conductive fluid may have electrically conductive metalparticles dispersed in a carrier fluid by means of a dispersant, such asmineral oil or the like.

Depending on the particular reactor core design and operating history,normal operating temperature of a sodium-cooled reactor core may berelatively high. For example, in the case of a 500 to 1,500 MWesodium-cooled reactor with mixed uranium-plutonium oxide fuel, thereactor core outlet temperature during normal operation may range fromapproximately 510° Celsius (i.e., 950° Fahrenheit) to approximately 550°Celsius (i.e., 1,020° Fahrenheit). On the other hand, during a LOCA(Loss Of Coolant Accident) or LOFTA (Loss of Flow Transient Accident)peak fuel cladding temperatures may reach about 600° Celsius (i.e.1,110° Fahrenheit) or more, depending on reactor core design andoperating history. Moreover, decay heat build-up during post-LOCA orpost-LOFTA scenarios and also during suspension of reactor operationsmay produce unacceptable heat accumulation. In some cases, therefore, itis appropriate to control coolant flow to the reactor core 20 duringboth normal operation and post accident scenarios.

As briefly mentioned above, the temperature profile in the reactor core20 varies as a function of location. In this regard, the temperaturedistribution in the reactor core 20 may closely follow the power densityspatial distribution in the reactor core 20. It will be appreciated thatthe power density near the center of the reactor core 20 is generallyhigher than the power density near the periphery of the reactor core20—particularly in the presence of a suitable neutron reflector orneutron breeding “blanket” surrounding the periphery of the reactor core20. Thus, it is to be expected that coolant flow parameters for thenuclear fission modules 30 near the periphery of the reactor core 20would be less than coolant flow parameters for the nuclear fissionmodules 30 near the center of the reactor core 20, especially at thebeginning of core life.

Hence, in this case, it would be unnecessary to provide the same oruniform coolant mass flow rate to each nuclear fission module 30. Asdescribed in detail hereinbelow, the electromagnetic flow regulator 490is provided to vary coolant flow to individual nuclear fission modules30 depending on location of the nuclear fission modules 30 in thereactor core 20 and/or depending on desired reactor operatingparameters.

Still referring to FIG. 4A as a brief overview, the heat-bearing coolantflows along a coolant flow stream or flow path 140 to an intermediateheat exchanger 150 and into a plenum volume 160 associated with theintermediate heat exchanger 150. After flowing into the plenum volume160, the coolant continues through the primary loop pipe 130. Thecoolant leaving plenum volume 160 has been cooled due to the heattransfer occurring in the intermediate heat exchanger 150. A pump 170 iscoupled to the primary loop pipe 130 and is in fluid communication withthe reactor coolant. The pump 170 pumps the reactor coolant through theprimary loop pipe 130, through the reactor core 20, along the coolantflow path 140, into the intermediate heat exchanger 150, and into theplenum volume 160.

Details regarding coupling of the electromagnetic flow regulator 490will be discussed later. In general, in embodiments in which theelectromagnetic flow regulator 490 is configured as the electromagneticflow regulator 490 a, the electromagnetic flow regulator 490 a iscapable of restricting flow of the electrically conductive reactorcoolant from the pump 170. The electromagnetic flow regulator 490 a maydevelop all or a portion of the pressure drop conventionally developedusing flow orificing. Use of the electromagnetic flow regulator 490 acan help reduce or, in some cases, may help eliminate pressure dropdependence from orificing.

In other embodiments in which the electromagnetic flow regulator 490 isconfigured into the electromagnetic flow regulator 490 b, theelectromagnetic flow regulator 490 b can help to establish, accelerate,or maintain flow velocity of the electrically conductive reactor coolantor can be used to restrict flow of the electrically conductive reactorcoolant.

Thus, it will be appreciated that the electromagnetic flow regulator 490can be configured as the electromagnetic flow regulator 490 a torestrict flow of the electrically conductive reactor coolant from thepump 170 to individual nuclear fission modules 30 or as theelectromagnetic flow regulator 490 b to either controllably supplementor restrict flow of the electrically conductive reactor coolant from thepump 170 to individual nuclear fission modules 30.

In some embodiments, the electromagnetic flow regulator 490 b can beconfigured to provide all or a portion of the flow established by thepump 170. In this regard, the pump 170 and the electromagnetic flowregulator 490 b can operate simultaneously or individually to provideand regulate coolant flow to the reactor core 20 and individual nuclearfission modules 30.

Referring still to FIG. 4A, a secondary loop pipe 180 is provided forremoving heat from the intermediate heat exchanger 150. The secondaryloop pipe 180 includes a secondary “hot” leg pipe segment 190 and asecondary “cold” leg pipe segment 200. The secondary cold leg pipesegment 200 is integrally formed with the secondary hot leg pipe segment190 so as to form a closed loop. The secondary loop pipe 180 contains afluid, which suitably may be liquid sodium or a liquid sodium mixture.The secondary hot leg pipe segment 190 extends from the intermediateheat exchanger 150 to a steam generator 210. In some embodiments, thesteam generator 210 may be configured as a steam generator andsuperheater combination.

After passing through the steam generator 210, the coolant flowingthrough the secondary loop pipe 180 and exiting the steam generator 210is at a lower temperature and enthalpy than before entering the steamgenerator 210 due to the heat transfer occurring within the steamgenerator 210. After passing through the steam generator 210, thecoolant is pumped by a pump 220 along the “cold” leg pipe segment 200,which extends into the intermediate heat exchanger 150 for transferringheat from the coolant flow path 140 to the secondary loop pipe 180.

A body of water 230 disposed in the steam generator 210 has apredetermined temperature and pressure. The fluid flowing through thesecondary hot leg pipe segment 190 will transfer its heat to the body ofwater 230, which is at a lower temperature than the fluid flowingthrough the secondary hot leg pipe segment 190. As the fluid flowingthrough the secondary hot leg pipe segment 190 transfers its heat to thebody of water 230, a portion of the body of water 230 will vaporize tosteam 240 according to the predetermined temperature and pressure withinthe steam generator 210. The steam 240 will then travel through a steamline 250 which has one end thereof in vapor communication with the steam240 and another end thereof in liquid communication with the body ofwater 230. A rotatable turbine 260 is coupled to the steam line 250,such that turbine the 260 rotates as the steam 240 passes therethrough.An electrical generator 270, which is coupled to the turbine 260, suchas by a rotatable turbine shaft 280, generates electricity as theturbine 260 rotates. In addition, a condenser 290 is coupled to thesteam line 250 and receives the steam passing through the turbine 260.The condenser 290 condenses the steam 240 to liquid water and passes anywaste heat to a heat sink 300, such as a cooling tower or the like,which is associated with the condenser 290. The liquid water condensedby the condenser 290 is pumped along the steam line 250 from thecondenser 290 to the steam generator 210 by a pump 310 interposedbetween the condenser 290 and the steam generator 210.

It will be appreciated that the reactor system 10 discussed above hasbeen given by way of a nonlimiting example. The reactor system 10 andits details have been explained by way of illustration only and not oflimitation.

It will be appreciated that the nuclear fission modules 30 may bearranged within the reactor core 20 in any configuration as desired. Forexample, in various embodiments the nuclear fission modules 30 may bearranged to define a hexagonally shaped configuration, acylindrically-shaped configuration, a parallelpiped shapedconfiguration, or the like.

Referring to FIG. 4C, regardless of the configuration chosen for thereactor core 20, spaced apart, longitudinally extending andlongitudinally movable control rods 360 are each disposed within acontrol rod guide tube or cladding (not shown). The control rods 360 aresymmetrically disposed within selected nuclear fission modules 30 andextend the length of a predetermined number of nuclear fission modules30. The control rods 360, which are shown disposed in a predeterminednumber of the nuclear fission modules 30, control the neutron fissionreaction occurring in nuclear fission modules 30. In other words, thecontrol rods 360 include a suitable neutron absorber material having anacceptably high neutron capture or absorption cross-section. In thisregard, the absorber material may be a metal or metalloid such aswithout limitation lithium, silver, indium, cadmium, boron, cobalt,hafnium, dysprosium, gadolinium, samarium, erbium, europium and mixturesthereof, or a compound or alloy such as without limitationsilver-indium-cadmium, boron carbide, zirconium diboride, titaniumdiboride, hafnium diboride, gadolinium titanate, dysprosium titanate andmixtures thereof.

The control rods 360 will controllably supply negative reactivity to thereactor core 20. Thus, the control rods 360 provide a reactivitymanagement capability to the reactor core 20. In other words, thecontrol rods 360 are capable of controlling the neutron flux profileacross the reactor core 20 and thus influence the temperature profileacross the reactor core 20.

Referring to FIGS. 4D and 4E, in some embodiments the nuclear fissionmodule 30 need not be neutronically active. In other words, the nuclearfission module 30 need not contain any fissile material. In this case,the nuclear fission module 30 may be a purely fertile assembly or apurely reflective assembly or a combination of both. In this regard, thenuclear fission module 30 may be a breeder nuclear fission moduleincluding breeder rods 370 (FIG. 4D) containing nuclear breedingmaterial or a reflective nuclear fission module including reflector rods380 (FIG. 4E) containing a reflective material.

In some other embodiments, the nuclear fission module 30 may containfuel rods 50 in combination with the breeder rods 370 (FIG. 4D) or thereflector rods 380 (FIG. 4E).

Thus, it will be appreciated that the nuclear fission module 30 mayinclude any suitable combination of nuclear fuel rods 50, control rods360, breeding rods 370, and reflector rods 380.

Regardless of whether or not the fuel rods 50 are included in thenuclear fission module 30, the fertile nuclear breeding material in thebreeding rods 370 may include without limitation thorium-232 and/oruranium-238. Also regardless of whether or not the fuel rods 50 areincluded in the nuclear fission module 30, the reflector material mayinclude a material such as without limitation beryllium. (Be), tungsten(W), vanadium (V), depleted or natural uranium (U), thorium (Th), leadalloys and mixtures thereof.

Referring now to FIG. 4F, regardless of the configuration selected forthe nuclear fission reactor core 20, the nuclear fission reactor core 20may be configured as a traveling wave nuclear fission reactor core. Inthis regard, a nuclear fission igniter 400, which may include isotopicenrichment of nuclear fissionable material such as without limitation,U-233, U-235 or Pu-239, is suitably located in any desired locationwithin the reactor core 20. By way of example only and not by way oflimitation, in a parallelpiped configuration as shown, the igniter 400may be located near a first end 350 that is opposite a second end 355 ofthe reactor core 20. Neutrons are released by the igniter 400. Theneutrons that are released by the igniter 400 are captured by fissileand/or fertile material within the nuclear fission modules 30 toinitiate the fission chain reaction. The igniter 400 may be removed oncethe fission chain reaction becomes self-sustaining, if desired.

The igniter 400 initiates a three-dimensional, traveling wave 410(sometimes referred to as a propagating wave or a burn wave) having awidth “x”. When the igniter 400 releases its neutrons to cause“ignition”, the burn wave 410 travels outwardly from the igniter 400toward the second end 355 of the reactor core 20, so as to form thetraveling or propagating burn wave 410. Thus, each nuclear fissionmodule 30 is capable of accepting at least a portion of the travelingburn wave 410 as the burn wave 410 propagates through the reactor core20.

Speed of the traveling burn wave 410 may be constant or non-constant.Thus, the speed at which the burn wave 410 propagates can be controlled.For example, longitudinal movement of the control rods 360 (not shown inFIG. 4F for clarity purposes) in a predetermined or programmed mannercan drive down or lower neutronic reactivity of the fuel rods 50 (notshown in FIG. 4F for clarity purposes) that are disposed in the nuclearfission modules 30. In this manner, neutronic reactivity of the fuelrods 50 that are presently being burned at the location of the burn wave410 can be driven down or lowered relative to neutronic reactivity of“unburned” fuel rods 50 ahead of the burn wave 410.

This result gives the burn wave propagation direction indicated by arrow420. Controlling reactivity in this manner enhances the propagation rateof the burn wave 410 subject to operating constraints for the reactorcore 20. For example, enhancing the propagation rate of the burn wave410 can help control burn-up above a minimum value needed forpropagation and a maximum value set, in part, by neutron fluencelimitations of reactor core structural materials. Such control ofpropagation of a traveling wave is described in U.S. patent applicationSer. No. 12/384,669, entitled TRAVELING WAVE NUCLEAR FISSION REACTOR,FUEL ASSEMBLY, AND METHOD OF CONTROLLING BURNUP THEREIN, naming CHARLESE. AHLFELD, JOHN ROGERS GILLELAND, RODERICK A. HYDE, MURIEL Y. ISHIKAWA,DAVID G. MCALEES, NATHAN P. MYHRVOLD, CHARLES WHITMER, LOWELL L. WOOD,JR., AND GEORGE B. ZIMMERMAN as inventors, filed Apr. 6, 2009, thecontents of which are hereby incorporated by reference.

The basic principles of a traveling wave nuclear fission reactor aredisclosed in more detail in U.S. patent application Ser. No. 11/605,943,entitled NUCLEAR POWER REACTOR FOR LONG-TERM OPERATION, naming RODERICKA. HYDE, MURIEL Y. ISHIKAWA, NATHAN P. MYHRVOLD, AND LOWELL L. WOOD, JR.as inventors, filed 28 Nov. 2006, the contents of which are herebyincorporated by reference.

Referring now to FIGS. 5A and 5B, each nuclear fission module 30 ismounted on a horizontally-extending reactor core lower support plate430. Only three adjacent nuclear fission modules 30 are shown, it beingunderstood that a greater or lesser number of nuclear fission modules 30may be present in the reactor core 20. The reactor core lower supportplate 430 suitably extends across a bottom portion of all of the nuclearfission modules 30.

The reactor core lower support plate 430 has a counter bore 440therethrough. The counter bore 440 has an open end 450 for allowing flowof coolant thereinto. Horizontally extending across a top portion orexit portion of all of the nuclear fission modules 30 and removablyconnected to all of the nuclear fission modules 30 may be a reactor coreupper support plate 460 that caps all of the nuclear fission modules 30.The reactor core upper support plate 460 also may define flow slots 470for allowing flow of coolant therethrough.

As discussed above, it is desirable to control the temperature of thereactor core 20 and the nuclear fission modules 30 therein, regardlessof the configuration selected for reactor core 20. For example,possibility of heat damage to reactor core structural materials may beincreased if the peak temperature exceeds material limits. Such peaktemperatures may undesirably reduce the operational life of structuressubjected to peak temperatures by altering the mechanical properties ofthe structures, particularly those properties relating to thermal creep.Also, reactor power density is limited, in part, by the ability of corestructural materials to withstand high peak temperatures without damage.Also, controlling reactor core temperature may be important forsuccessfully conducting tests, such as tests to determine effects oftemperature on reactor materials.

In addition, the nuclear fission modules 30 disposed at or near thecenter of the reactor core 20 may generate more heat than the nuclearfission modules 30 disposed at or near the periphery of the reactor core20. Therefore, it would be inefficient to supply a uniform coolant massflow rate across the reactor core 20 because higher heat flux nuclearfission modules 30 near the center of the reactor core 20 would involvea higher coolant mass flow rate than the nuclear fission modules 30 nearthe periphery of the reactor core 20, particularly at the beginning ofcore life.

Referring now to FIGS. 4A, 5A, and 5B, the primary loop pipe 130delivers reactor coolant to the nuclear fission modules 30 along acoolant flow path or fluid stream indicated by directional flow arrows140. The primary coolant then continues along the coolant flow path 140and through an open end 450 that is formed in the core lower supportplate 430. The core lower support plate 430 may also form a portion of acore inlet flow plenum. As described in more detail hereinbelow, thereactor coolant can be used to remove heat from or cool selected ones ofthe nuclear fission modules 30, such as nuclear fission modules 30disposed in a traveling wave nuclear fission reactor core at thelocation or vicinity of traveling burn wave 410 (not shown in FIGS. 4A,5A, or 5B) within the traveling wave nuclear fission reactor core. Inother words, in some cases the nuclear fission module 30 may beselected, at least in part, on the basis of whether or not the burn wave410 is located, detected, or otherwise is disposed within or in thevicinity of or at a location relative to the nuclear fission module 30,as described in more detail below.

Referring additionally to FIG. 4F, in order to regulate flow ofelectrically conductive reactor coolant to the selected one of nuclearfission modules 30, an electromagnetic flow regulator 490 and associatedcontrol system is coupled to at least one nuclear fission module 30. Itis again emphasized that, although the discussion and illustrations aredirected to the electromagnetic flow regulator 490, except ifspecifically indicated otherwise the discussion and illustrations areintended to encompass the electromagnetic flow regulators 490 a and 490b. In some embodiments, the electromagnetic flow regulator 490 may beintegrally connected to the nuclear fission module 30. In some otherembodiments, the electromagnetic flow regulator 490 may be connected tothe lower support plate 430.

In some embodiments, the electromagnetic flow regulator 490 is adaptedto supply a relatively lesser amount of coolant to the nuclear fissionmodule 30 when a lesser amount of the burn wave 410 (i.e., lesserintensity of the burn wave 410) is present within or at a locationrelative to the nuclear fission module 30. On the other hand, in someembodiments the electromagnetic flow regulator 490 is adapted to supplya relatively greater amount of coolant to the nuclear fission module 30when a greater amount of the burn wave 410 (i.e., greater intensity ofthe burn wave 410) is present within or at least at a location relativeto the nuclear fission module 30. Presence and intensity of the burnwave 410 may be identified by any one or more suitable parameter, suchas without limitation temperature within or relative to the nuclearfission module 30, neutron flux within or relative to the fission module30, neutron fluence within or relative to the fission module 30, powerlevel within the nuclear fission module 30, a characteristic isotopewithin the nuclear fission module 30, pressure within the nuclearfission module 30, flow rate of the electrically conductive fluid withinthe nuclear fission module 30, heat generation rate within the nuclearfission module 30, a width “x” of the burn wave 410, and/or othersuitable operating parameter associated with the nuclear fission module30.

Referring additionally to FIG. 5C, in some embodiments theelectromagnetic flow regulator 490 may be adapted to be operated inresponse to an operating parameter associated with the nuclear fissionmodule 30. In such embodiments, not only does the electromagnetic flowregulator 490 control flow of the coolant in response to the location ofthe burn wave 410 relative to the nuclear fission modules 30, theelectromagnetic flow regulator 490 also controls flow of the coolant inresponse to certain operating parameters associated with the reactorcore 20 and the nuclear fission module 30. In this regard, at least onesensor 500 may be disposed in or near the nuclear fission module 30 tosense status of the operating parameter.

For example, the operating parameter sensed by the sensor 500 may be acurrent temperature associated with the nuclear fission module 30. Inorder to sense temperature, the sensor 500 may be a thermocouple deviceor temperature sensor that may be available from Thermocoax,Incorporated located in Alpharetta, Ga. U.S.A.

As another example, the operating parameter sensed by the sensor 500 maybe neutron flux in the nuclear fission module 30. In order to senseneutron flux, the sensor 500 may be a “PN9EB20/25” neutron fluxproportional counter detector or the like, such as may be available fromCentronic House, Surrey, England.

As another example, the operating parameter sensed by the sensor 500 maybe a characteristic isotope in the nuclear fission module 30. Thecharacteristic isotope may be a fission product, an activated isotope, atransmuted product produced by breeding or other characteristic isotope.

As another example, the operating parameter sensed by the sensor 500 maybe neutron fluence in the nuclear fission module 30. As is known,neutron fluence is defined as the neutron flux integrated over a certaintime period and represents the number of neutrons per unit area thatpassed during that time period.

As another example, the operating parameter sensed by the sensor 500 maybe fission module pressure. In some embodiments, the sensed fissionmodule pressure fission module pressure may be a dynamic fluid pressure.Given by way of nonlimiting examples by way of illustration and not oflimitation, fission module pressure may be a dynamic fluid pressure ofapproximately 10 bars (i.e., approximately 145 psi) for an illustrativesodium cooled reactor or approximately 138 bars (i.e., approximately2000 psi) for an illustrative pressurized “light” water cooled reactorduring normal operation.

In some other embodiments, fission module pressure that is sensed by thesensor 500 may be a static fluid pressure or a fission product pressure.In order to sense either dynamic or static fluid pressure, the sensor500 may be a custom-designed pressure detector that may be availablefrom Kaman Measuring Systems, Incorporated located in Colorado Springs,Colo. U.S.A.

As another example, the operating parameter sensed by the sensor 500 maybe flow rate of the electrically conductive fluid within the nuclearfission module 30. In such embodiments, the sensor 500 may be a suitableflow meter such as a “BLANCETT 1100 TURBINE FLOW METER”, available fromInstrumart, Incorporated located in Williston, Vt. U.S.A.

It will be appreciated that pressure or mass flow sensors are locatedthroughout operating nuclear reactor systems, such as in the primaryloop coolant pipe 130 or the secondary loop coolant pipe 180, inaddition to being located within or in the vicinity of the nuclearfission module 30. Such a sensor will be used to detect flow conditionsthroughout the coolant system.

In addition, the operating parameter to be sensed by the sensor 500 maybe determined by a suitable computer-based algorithm (not shown).

In some embodiments, the operating parameter may be selected byoperator-initiated action. In such embodiments, the electromagnetic flowregulator 490 is capable of being modified in response to any suitableoperating parameter determined by a human operator.

In some other embodiments, the electromagnetic flow regulator 490 iscapable of being modified in response to an operating parameter selectedby a suitable feedback control system. For example, in such embodimentssuch a feedback control system may sense changes in temperature andmodify coolant flow in response to a changing temperature-sensitivepower distribution. Such control could be performed autonomously withsuitable feedback controls established between the sensinginstrumentation and an electromagnetic flow regulator control system.

In some other embodiments, the electromagnetic flow regulator 490 iscapable of being modified in response to an operating parameterdetermined by an automated control system. As an example, in suchembodiments the electromagnetic flow regulation may be modified toprovide unimpeded flow to the nuclear fission modules 30 during a coreshut-down event initiated by an accident scenario, such as a loss ofoff-site power or the like. In this manner, conditions for naturalcirculation flow can be established via the automated control system ina passive manner, specifically during a loss of power to theelectromagnetic flow regulators 490. Additionally, in some embodimentsthe automated control system may include a source of back-up electricalpower which can be provided to the electromagnetic flow regulators 490 bto maintain forced flow in response to accidents such as loss ofoff-site power.

Moreover, in some embodiments the electromagnetic flow regulator 490 iscapable of being modified in response to a change in decay heat. In thisregard, decay heat decreases in the “tail” of the burn wave 410.Detection of the presence of the tail of the burn wave 410 is used todecrease coolant flow rate over time to account for the decrease indecay heat found in the tail of the burn wave 410. This is particularlythe case when the nuclear fission module 30 resides behind the burn wave410. In this case, the electromagnetic flow regulator 490 can bemodified in response to changes in decay heat output of the nuclearfission module 30 as the distance of the nuclear fission module 30 fromthe burn wave 410 changes. Sensing status of such operating parameterscan facilitate suitable control and modification of the electromagneticflow regulator 490 and thus suitable control and modification oftemperature in the reactor core 20.

In some embodiments, the electromagnetic flow regulator 490 is capableof controlling or regulating flow of the coolant according to timing ofwhen the traveling burn wave 410 arrives at and/or departs from thenuclear fission module 30. Also, in some embodiments the electromagneticflow regulator 490 is capable of controlling or regulating flow of thecoolant according to timing of when the traveling burn wave 410 isproximate to, in the vicinity of, or generally at a location relative tothe nuclear fission module 30. In some embodiments, the electromagneticflow regulator 490 is also capable of controlling or regulating flow ofthe coolant according to the width x of the burn wave 410.

In such embodiments, arrival and departure of the burn wave 410, as theburn wave 410 travels through the nuclear fission module 30, may bedetected by sensing any one or more of the operating parametersdiscussed above. For example, the electromagnetic flow regulator 490 maybe capable of controlling or regulating flow of the coolant according totemperature sensed in the nuclear fission module 30, in which case thetemperature may be indicative of the nearby presence of the propagatingor traveling burn wave 410. As another example, the electromagnetic flowregulator 490 may be capable of controlling or regulating flow of thecoolant according to temperature sensed in the nuclear fission module30, in which case the temperature may be indicative of a stationary burnwave 410.

The nuclear fission module 30 that is to receive the variable flow isselected on the basis of the desired value for the operating parameterin the nuclear fission module 30 compared to the value of the operatingparameter that is actually sensed in the nuclear fission module 30. Asdescribed in more detail presently, fluid flow to the nuclear fissionmodule 30 is adjusted to bring the actual value for the operatingparameter into substantial agreement (e.g., plus or minus 5% agreementin terms of the operating parameter) with the desired value for theoperating parameter.

In such embodiments, the electromagnetic flow regulator 490 is capableof controlling or regulating flow of the coolant according to the actualvalue of the operating parameter sensed by the sensor 500 compared to apredetermined desired value for the operating parameter. An appreciablemismatch between the actual value and the desired value of the operatingparameter may be a reason to adjust the electromagnetic flow regulator490 to bring the actual value into substantial agreement with thedesired value.

Thus, use of the electromagnetic flow regulator 490 may be arranged toachieve variable coolant flow on a module-by-module (and in some casesfuel assembly-by-fuel assembly) basis. This allows coolant flow to bevaried across the reactor core 20 according to the location of the burnwave 410 or the actual values of operating parameters compared todesired values of operating parameters in the reactor core 20.

It will be appreciated that the electromagnetic flow regulator 490 maybe coupled to the nuclear fission modules 30 in any manner as desiredfor a particular application. To that end, several illustrative exampleswill be set forth below by way of illustration only and not oflimitation.

Referring to FIG. 6A, in some embodiments an individual electromagneticflow regulator 490 diverts at least one portion of the electricallyconductive fluid along at least one of diversion flow pathways 700 thatextend from the individual electromagnetic flow regulator 490 torespective ones of the nuclear fission modules 30. Flow of theelectrically conductive fluid from the individual electromagnetic flowregulator 490 will bifurcate and flow along conduits 710 a and 710 b aswell as flow directly into the nuclear fission module 30 that isvertically aligned with and located above electromagnetic flow regulator490.

A valve 720, such as a backflow prevention valve, may be disposed ineach of the conduits 710 a and 710 b for controlling flow of theelectrically conductive fluid in conduits 710 a and 710 b, if desired.Each of the valves 720 may be selectively controllable by the controlunit 610.

Only three nuclear fission modules 30 and only a pair of the conduits710 a and 710 b are shown as being coupled to the individualelectromagnetic flow regulator 490. However, it will be appreciated thatthere may be any number of the nuclear fission modules 30 and conduits710 a and 710 b coupled to the individual electromagnetic flow regulator490 as desired. Therefore, it will be appreciated that a singleelectromagnetic flow regulator 490 can be used to supply electricallyconductive fluid to more than one nuclear fission module 30.

Referring to FIG. 6B, in some other embodiments the electromagnetic flowregulator 490 allows flow of the electrically conductive fluid to bypassselected nuclear fission modules 30. In such embodiments theelectromagnetic flow regulator 490 diverts at least one portion of theelectrically conductive fluid, so as to bypass selected nuclear fissionmodules 30. The electromagnetic flow regulator 490 diverts at least oneportion of the electrically conductive fluid along diversion flowpathways 740. That is, flow of the electrically conductive fluid willbifurcate from each electromagnetic flow regulator 490 and flow along apair of conduits 750 a and 750 b for bypassing the selected nuclearfission modules 30.

A valve 760, such as a backflow prevention valve, may be disposed ineach of the conduits 750 a and 750 b for controlling flow of theelectrically conductive fluid in the conduits 750 a and 750 b, ifdesired. Each of the valves 760 may be selectively controllable by thecontrol unit 610. Each of the conduits 750 a and 750 b terminates in anupper plenum 770. The upper plenum 770 combines the flow of theelectrically conductive fluid from the conduits 750 a and 750 b so thata single flow stream 140 is supplied to intermediate heat exchanger 150(FIG. 4A).

In FIG. 6B, only three nuclear fission modules 30, only threeelectromagnetic flow regulators 490, only a pair of the valves 760, andonly a pair of the conduits 750 a and 750 b are shown. However, it willbe appreciated that there may be any number and combination of fissionmodules 30, electromagnetic flow regulators 490, valves 760, andconduits 750 a and 750 b as desired. Therefore, it will be appreciatedthat the electrically conductive fluid may bypass any desired number ofnuclear fission modules 30.

Referring to FIG. 6C, in some embodiments the electromagnetic flowregulator 490 selectively controls flow of the electrically conductivefluid to individual nuclear fission modules 30. In such embodiments, theelectromagnetic flow regulator 490 diverts at least one portion of theelectrically conductive fluid, so as to direct coolant flow toindividual nuclear fission modules 30.

The electromagnetic flow regulator 490 diverts at least one portion ofthe electrically conductive fluid along a diversion flow pathway 790 aand along a diversion flow pathway 790 b. The diversion flow pathway 790b may be oriented to conduct fluid flow in a direction opposite thedirection of fluid flow in the diversion flow pathway 790 a. In thisregard, the electrically conductive fluid enters a lower plenum 800along the flow path 140.

A conduit 810 a that is in fluid communication with the electricallyconductive fluid in the lower plenum 800 receives the electricallyconductive fluid from the lower plenum 800 and conducts the electricallyconductive fluid along the diversion flow pathway 790 a. A conduit 810 bis also in fluid communication with the electrically conductive fluid inthe lower plenum 800 and is configured to return the electricallyconductive fluid to the lower plenum 800 along the diversion flowpathway 790 b. The conduit 810 a terminates in an intermediate plenum830 from which flow of the electrically conductive fluid is supplied tothe electromagnetic flow regulator 490.

A valve 840 a, such as a backflow prevention valve, may be disposed inthe conduit 810 a for controlling coolant flow in the conduit 810 a.Another valve 840 b, such as a backflow prevention valve, may bedisposed in the conduit 810 b for controlling flow of the electricallyconductive fluid in the conduit 810 b. Another valve 840 c, such as abackflow prevention valve, is interposed between the electromagneticflow regulator 490 and the nuclear fission module 30 for controllingflow of the electromagnetic fluid from the electromagnetic flowregulator 490 to the nuclear fission module 30.

Each of valves 840 a, 840 b and 840 c may be selectively controllable bymeans of the control unit 610. In this regard, when the valves 840 a and840 c are opened and the valve 840 c is closed by the control unit 610,the electrically conductive fluid will freely flow through the conduit810 a, into the intermediate plenum 830, and then to the nuclear fissionmodule 30. When the valve 840 c is closed and the valves 840 a and 840 bare opened by the control unit 610, the electrically conductive fluidwill not flow to the nuclear fission module 30. In this latter instance,the electrically conductive fluid is returned to the lower plenum 800.

In some embodiments, a conduit 842, which may have a backflow preventionvalve 844 disposed therein, may be provided in fluid communication withthe electrically conductive fluid in the lower plenum 800. The conduit842 terminates in the intermediate plenum 830. When the valve 844 isopen, the electrically conductive fluid is supplied to the intermediateplenum 830 and the electromagnetic flow regulator 490, which in turnsupplies the electrically conductive fluid to the nuclear fission module30. When the valve 844 is closed, the electrically conductive fluid isnot supplied to the intermediate plenum 830 and the electromagnetic flowregulator 490, and hence the electrically conductive fluid is notsupplied to the'nuclear fission module 30.

Only three nuclear fission modules 30, only three electromagnetic flowregulators 490, only conduits 810 a, 810 b, and 842 b, and only valves840 a, 840 b, 840 c, and 844 are shown. However, it will be appreciatedthat there may be any number and combination of fission modules 30,electromagnetic flow regulators 490, conduits 810 a, 810 b, and 842, andvalves 840 a, 840 b, 840 c, and 844 as desired. Therefore, it will beappreciated that the electrically conductive fluid may flow from thelower plenum 800 to any number of selected nuclear fission modules 30 orreturn from any number of selected nuclear fission modules 30 to thelower plenum 800.

Referring to FIGS. 6D and 6E, in some embodiments the reactor core 20defines a single coolant flow zone 930 assigned to the entirety of thereactor core 20. An inlet plenum 940 is coupled to the reactor core 20.The electromagnetic flow regulator 490 is coupled to the reactor core 20and has a coolant flow opening 950 in fluid communication with the inletplenum 940. Hence, electromagnetic flow regulator 490 will supply theelectrically conductive fluid into the inlet plenum 940. Theelectrically conductive fluid will fill the inlet plenum 940 and thenflow to the nuclear fission modules 30 located in the coolant flow zone930. In such embodiments, a single electromagnetic flow regulator 490can regulate the flow of electrically conductive coolant to all nuclearfission modules 30 in the reactor core 20.

Referring to FIGS. 6F and 6G, in some embodiments the reactor core 20includes coolant flow zones 960 a, 960 b, 960 c, 960 d, 960 e, 960 f,and 960 g. Adjacent coolant flow zones may be separated by a partition970, if desired. The partition 970 may be made from a material having alow absorption cross section for neutrons in order to reduceinterference with the fission chain reaction process.

In this regard, the partition 970 may be made from pure aluminum; asuitable aluminum alloy, such as aluminum alloy No. 1050 comprising ironof about 0.40 weight percent; silicon of about 0.25 weight percent;titanium of about 0.05 weight percent; magnesium of about 0.05 weightpercent; manganese of about 0.05 weight percent; copper of about 0.05weight percent; and the remainder being pure aluminum. The partition 970may also be made from stainless steel comprising carbon of about 0.55weight percent; manganese of about 0.90 weight percent; sulfur of about0.05 weight percent; phosphorus of about 0.04 weight percent; and ironof about 98.46 percent.

The coolant flow zones, which are defined by the partitions 970, allowan operator of the reactor system 10 to tailor coolant flow on a reactorcore zone-by-zone basis rather than having individual electromagneticflow regulators 490 coupled to individual nuclear fission modules 30.

Still referring to FIGS. 6F and 6G, inlet plenums 980 are coupled torespective ones of the coolant flow zones 960 a, 960 b, 960 c, 960 d,960 e, 960 f, and 960 g, such as by conduits 1000 a, 1000 b, 1000 c,1000 d, 1000 e, 1000 f, and 1000 g. The conduits 1000 a, 1000 b, 1000 c,1000 d, 1000 e, 1000 f , and 1000 g are, in turn, coupled to respectiveelectromagnetic flow regulators 490. Thus, the electromagnetic flowregulators 490 are coupled to respective coolant flow zones 960 a, 960b, 960 c, 960 d, 960 e, 960 f, and 960 g.

Each electromagnetic flow regulator 490 has a coolant flow opening 1005in fluid communication with the inlet plenum 980. Hence, theelectromagnetic flow regulator 490 will supply the electricallyconductive fluid into the inlet plenum 980. The electrically conductivefluid will fill the inlet plenum 980 and then flow to the nuclearfission modules 30 located in the coolant flow zones 960 a, 960 b, 960c, 960 d, 960 e, 960 f, and 960 g. The electrically conductive fluid mayflow from at least some of the electromagnetic flow regulators 490 viathe associated conduits 1000 a, 1000 b, and 1000 c that extend from theelectromagnetic flow regulator 490 to their respective inlet plenums980.

Referring to FIG. 6H, in some embodiments the reactor core 20 includescoolant flow zones 1020 a, 1020 b, and 1020 c. Adjacent coolant flowzones may be separated by a partition 1030 that is of low neutronabsorptivity as described above, if desired. Electromagnetic flowregulators 490 are coupled to respective coolant flow zones 1020 a, 1020b, and 1020 c, such as by respective inlet plenums, which may have aconfiguration substantially similar to that shown in FIG. 6G. Eachelectromagnetic flow regulator 490 has conduits 1040 a, 1040 b, and 1040c in fluid communication with the respective inlet plenums. Hence, theelectromagnetic flow regulator 490 will supply the electricallyconductive fluid into the inlet plenums. The electrically conductivefluid will fill the inlet plenums and then flow to the nuclear fissionmodules 30 located in the coolant flow zones 1020 a, 1020 b, and 1020 c.

Referring to FIG. 6I, in some embodiments the reactor core 20 definescoolant flow zones 1060 a, 1060 b, 1060 c, 1060 d, 1060 e, and 1060 f.Adjacent coolant flow zones may be separated by a partition 1070 that isof low neutron absorptivity as described above, if desired.

Electromagnetic flow regulators 490 are coupled to respective coolantflow zones 1060 a, 1060 b, 1060 c, 1060 d, 1060 e, and 1060 f, such asby respective inlet plenums. The electromagnetic flow regulators 490have respective coolant flow conduits 1080 a, 1080 b, 1080 c, 1080 d,1080 e, and 1080 f in fluid communication with the respective inletplenums. Hence, the electromagnetic flow regulator 490 will supply theelectrically conductive fluid into the inlet plenums. The electricallyconductive fluid will fill the inlet plenums and then flow to thenuclear fission modules 30 located in the coolant flow zones 1060 a,1060 b, 1060 c, 1060 d, 1060 e, and 1060 f.

Referring to FIG. 6J, in some embodiments the nuclear fission reactorcore 20 defines non-partitioned flow zones 1100 c and 1100 d that arepartitioned from flow zones 1100 a and 1100 b. Electromagnetic flowregulators 490 are coupled to respective coolant flow zones 1100 a, 1100b, 1100 c, and 1100 d, such as by respective inlet conduits. Theelectromagnetic flow regulators 490 have respective coolant flowopenings 1120 a, 1120 b, 1120 c, 1120 d, 1120 e, 1120 f, 1120 g, 1120 hhand 1120 i in fluid communication with their respective coolant flowzones 1100 a, 1100 b, 1100 c, and 1100 d. Hence, the electromagneticflow regulator 490 will supply the electrically conductive fluid intothe coolant flow zones 1100 a, 1100 b, 1100 c, and 1100 d. Theelectrically conductive fluid will fill the inlet plenums and then flowto the nuclear fission modules 30 located in the coolant flow zones 1100a, 1100 b, 1100 c, and 1100 d.

It will be appreciated that a system for electromagnetically regulatingflow of an electrically conductive reactor coolant may include a sourceof electrical power, such as the power supply 590, and theelectromagnetic flow regulator 490. Another system forelectromagnetically regulating flow of an electrically conductive fluidmay include a source of electrical power, such as the power supply 590,and the electromagnetic flow regulator 490 a. Similarly, another systemfor electromagnetically regulating flow of an electrically conductivefluid may include a source of electrical power, such as the power supply590, and the electromagnetic flow regulator 490 b. Any of the abovesystenis may also include a controller, such as the control unit 610,and/or a sensor, such as the sensor 500, if desired. The power supply590, the control unit 610, the sensor 500, and the electromagnetic flowregulators 490, 490 a, and 490 b have been discussed above. Details oftheir construction and operation need not be repeated for anunderstanding.

Now that illustrative details have been set forth above regardingconstruction and operation of the electromagnetic flow regulators 490,490 a, and 490 b, and regarding various nuclear fission reactors thatinclude the electromagnetic flow regulators 490, 490 a, and 490 b,various methods for electromagnetically regulating flow of anelectrically conductive reactor coolant will be set forth.

Referring now to FIG. 7A, a method 7000 is provided for regulating flowof an electrically conductive reactor coolant in a nuclear fissionreactor. The method 7000 starts at a block 7002. At a block 7004electrically conductive reactor coolant is flowed to a nuclear fissionmodule in a nuclear fission reactor. At a block 7006 flow of theelectrically conductive reactor coolant is electromagnetically regulatedto the nuclear fission module with an electromagnetic flow regulatorcoupled to the nuclear fission module. The method 7000 stops at a block7008.

Referring additionally to FIG. 7B, electromagnetically regulating flowof the electrically conductive reactor coolant to the nuclear fissionmodule with an electromagnetic flow regulator coupled to the nuclearfission module at the block 7006 may include flowing an electricallyconductive reactor coolant through a reactor coolant inlet path that isdefined through a plurality of magnetic conductors at a block 7010.Electromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7006may also include generating a Lorentz force that regulates flow of theelectrically conductive reactor coolant through the reactor coolantinlet path at a block 7012. Electromagnetically regulating flow of theelectrically conductive reactor coolant to the nuclear fission modulewith an electromagnetic flow regulator coupled to the nuclear fissionmodule at the block 7006 may also include flowing the electricallyconductive reactor coolant along a reactor coolant flow path definedalong the plurality of magnetic conductors and that is substantiallyorthogonal to the reactor coolant inlet path at a block 2014.

Referring additionally to FIG. 7C, in some embodiments generating aLorentz force that regulates flow of the electrically conductive reactorcoolant through the reactor coolant inlet path at the block 7012 mayinclude generating a Lorentz force that resists flow of the electricallyconductive reactor coolant through the reactor coolant inlet path at ablock 7016. For example and referring additionally to FIG. 7D,generating a Lorentz force that resists flow of the electricallyconductive reactor coolant through the reactor coolant inlet path at theblock 7016 may include generating at least one magnetic field at thereactor coolant inlet path by an electrical current-carrying fieldgeneration winding disposed outboard of the plurality of magneticconductors at a block 7018.

In some other embodiments and referring now to FIGS. 7A, 7B, and 7E,generating a Lorentz force that regulates flow of the electricallyconductive reactor coolant through the reactor coolant inlet path at theblock 7012 may include generating a Lorentz force that forces flow ofthe electrically conductive reactor coolant through the reactor coolantinlet path at a block 7020. For example and referring additionally toFIG. 7F, generating a Lorentz force that forces flow of the electricallyconductive reactor coolant through the reactor coolant inlet path at theblock 7020 may include generating at least one magnetic field at thereactor coolant inlet path by a first plurality of electricalcurrent-carrying conductors that are disposed inboard of the pluralityof magnetic conductors and a second plurality of electricalcurrent-carrying conductors that are disposed outboard of the pluralityof magnetic conductors at a block 7022.

Referring now to FIGS. 7A and 7G, in some embodiments at least oneportion of an electrically conductive reactor coolant may be diverted ata block 7024.

For example and referring additionally to FIG. 7H, in some embodimentsdiverting at least one portion of an electrically conductive reactorcoolant at the block 7024 may include diverting the at least one portionof the electrically conductive reactor coolant along at least one of aplurality of diversion flow pathways extending from the electromagneticflow regulator to respective ones of a plurality of the nuclear fissionmodules at a block 7026.

As another example and referring now to FIGS. 7A, 7G, and 7I, in someother embodiments diverting at least one portion of an electricallyconductive reactor coolant at the block 7024 may include diverting theat least one portion of the electrically conductive reactor coolantalong a diversion flow pathway bypassing the nuclear fission module at ablock 7028.

As another example and referring now to FIGS. 7A, 7G, and 7J, in someother embodiments diverting at least one portion of an electricallyconductive reactor coolant at the block 7024 may include diverting theat least one portion of the electrically conductive reactor coolantalong a diversion flow pathway having a first direction and a seconddirection at a block 7030.

Referring now to FIGS. 7A and 7K, in some embodiments at least oneoperating parameter associated with the nuclear fission module may besensed at a block 7032.

In some such cases and referring additionally to FIG. 7L,electromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7006may include electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module andresponsive to the operating parameter associated with the nuclearfission module at a block 7034.

The operating parameter associated with the nuclear fission module mayinclude any parameter as desired. In various embodiments, the operatingparameter may include without limitation temperature, neutron flux,neutron fluence, a characteristic isotope, pressure, and/or flow rate ofthe electrically conductive reactor coolant.

In some other embodiments and referring to FIGS. 7A and 7M, flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor at the block 7004 may include flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor, the nuclear fission module being associatedwith a burn wave present at a location relative to the nuclear fissionmodule, the burn wave having a width, at a block 7036.

Referring additionally to FIG. 7N, in some such caseselectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7036may include electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module inresponse to the burn wave present at the location relative to thenuclear fission module at a block 7038. For example and referringadditionally to FIG. 7O, electromagnetically regulating flow of theelectrically conductive reactor coolant to the nuclear fission modulewith an electromagnetic flow regulator coupled to the nuclear fissionmodule in response to the burn wave present at the location relative tothe nuclear fission module at the block 7038 may includeelectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module in response to thewidth of the burn wave at a block 7040.

Referring now to FIGS. 7A and 7P, in some embodiments flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor at the block 7004 may include flowingelectrically conductive reactor coolant to a plurality of nuclearfission modules defining a reactor core having a coolant flow zone at ablock 7042.

Referring to FIGS. 7A and 7Q, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7004 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a single coolant flow zone at a block7044.

Referring to FIGS. 7A and 7R, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7004 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a plurality of coolant flow zones at ablock 7046.

Referring to FIGS. 7A and 7S, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7004 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a plurality of coolant flow zonesseparated by respective ones of a plurality of partitions at a block7048.

Referring now to FIG. 7T, an illustrative method 7100 is provided forregulating flow of an electrically conductive reactor coolant in anuclear fission reactor. The method 7100 starts at a block 7102. At ablock 7104, electrically conductive reactor coolant is flowed to anuclear fission module in a nuclear fission reactor. At a block 7106flow of the electrically conductive reactor coolant to the nuclearfission module is electromagnetically regulated with an electromagneticflow regulator coupled to the nuclear fission module.Electromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7106includes flowing an electrically conductive reactor coolant through aplurality of flow holes defined through a plurality of magneticconductors. Electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module atthe block 7106 also includes generating a Lorentz force that resistsflow of the electrically conductive reactor coolant through theplurality of flow holes. Electromagnetically regulating flow of theelectrically conductive reactor coolant to the nuclear fission modulewith an electromagnetic flow regulator coupled to the nuclear fissionmodule at the block 7106 also includes flowing the electricallyconductive reactor coolant along a reactor coolant flow path definedalong the plurality of magnetic conductors and that is substantiallyorthogonal to flow of the electrically conductive reactor coolantthrough the plurality of flow holes. The method 7100 stops at a block7108.

Referring additionally to FIG. 7U, in some embodiments generating aLorentz force that resists flow of the electrically conductive reactorcoolant through the plurality of flow holes at the block 7106 mayinclude generating at least one magnetic field at the plurality of flowholes by an electrical current-carrying field generation windingdisposed outboard of the plurality of magnetic conductors at a block7110.

Referring now to FIGS. 7T and 7V, in some embodiments at least oneportion of an electrically conductive reactor coolant may be diverted ata block 7112.

For example and referring additionally to FIG. 7W, in some embodimentsdiverting at least one portion of an electrically conductive reactorcoolant at the block 7112 may include diverting the at least one portionof the electrically conductive reactor coolant along at least one of aplurality of diversion flow pathways extending from the electromagneticflow regulator to respective ones of a plurality of the nuclear fissionmodules at a block 7114.

As another example and referring now to FIGS. 7T, 7V, and 7X, in someother embodiments diverting at least one portion of an electricallyconductive reactor coolant at the block 7112 may include diverting theat least one portion of the electrically conductive reactor coolantalong a diversion flow pathway bypassing the nuclear fission module at ablock 7116.

As another example and referring now to FIGS. 7T, 7V, and 7Y, in someother embodiments diverting at least one portion of an electricallyconductive reactor coolant at the block 7112 may include diverting theat least one portion of the electrically conductive reactor coolantalong a diversion flow pathway having a first direction and a seconddirection at a block 7118.

Referring now to FIGS. 7T and 7Z, in some embodiments at least oneoperating parameter associated with the nuclear fission module may besensed at a block 7120.

Referring additionally to FIG. 7AA, in such cases electromagneticallyregulating flow of the electrically conductive reactor coolant to thenuclear fission module with an electromagnetic flow regulator coupled tothe nuclear fission module at the block 7106 may includeelectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module and responsive tothe operating parameter associated with the nuclear fission module at ablock 7122.

The operating parameter associated with the nuclear fission module mayinclude any parameter as desired. In various embodiments, the operatingparameter may include without limitation temperature, neutron flux,neutron fluence, a characteristic isotope, pressure, and/or flow rate ofthe electrically conductive reactor coolant.

In some other embodiments and referring to FIGS. 7T and 7AB, flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor at the block 7104 may include flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor, the nuclear fission module being associatedwith a burn wave present at a location relative to the nuclear fissionmodule, the burn wave having a width, at a block 7124.

Referring additionally to FIG. 7AC, in some such caseselectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7124may include electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module inresponse to the burn wave present at the location relative to thenuclear fission module at a block 7126. For example and referringadditionally to FIG. 7AD, electromagnetically regulating flow of theelectrically conductive reactor coolant to the nuclear fission modulewith an electromagnetic flow regulator coupled to the nuclear fissionmodule in response to the burn wave present at the location relative tothe nuclear fission module at the block 7126 may includeelectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module in response to thewidth of the burn wave at a block 7128.

Referring now to FIGS. 7T and 7AE, in some embodiments flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor at the block 7104 may include flowingelectrically conductive reactor coolant to a plurality of nuclearfission modules defining a reactor core having a coolant flow zone at ablock 7130.

Referring to FIGS. 7T and 7AF, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7104 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a single coolant flow zone at a block7132.

Referring to FIGS. 7T and 7AG, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7104 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a plurality of coolant flow zones at ablock 7134.

Referring to FIGS. 7T and 7AH, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7104 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a plurality of coolant flow zonesseparated by respective ones of a plurality of partitions at a block7136.

Referring now to FIG. 7I, an illustrative method 7200 is provided forregulating flow of an electrically conductive reactor coolant in anuclear fission reactor. The method 7200 starts at a block 7202. At ablock 7204, electrically conductive reactor coolant is flowed to anuclear fission module in a nuclear fission reactor. At a block 7206flow of the electrically conductive reactor coolant to the nuclearfission module is electromagnetically regulated with an electromagneticflow regulator coupled to the nuclear fission module.Electromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7206includes flowing an electrically conductive reactor coolant through aplurality of flow holes defined through a plurality of magneticconductors. Electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module atthe block 7206 also includes generating a Lorentz force that forces flowof the electrically conductive reactor coolant through the plurality offlow holes. Electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module atthe block 7206 also includes flowing the electrically conductive reactorcoolant along a reactor coolant flow path defined along the plurality ofmagnetic conductors and that is substantially orthogonal to flow of theelectrically conductive reactor coolant through the plurality of flowholes. The method 7200 stops at a block 7208.

Referring additionally to FIG. 7AJ, in some embodiments generating aLorentz force that forces flow of the electrically conductive reactorcoolant through the plurality of flow holes at the block 7206 mayinclude generating at least one magnetic field at the plurality of flowholes by a first plurality of electrical current-carrying conductorsthat are disposed inboard of the plurality of magnetic conductors and asecond plurality of electrical current-carrying conductors that aredisposed outboard of the plurality of magnetic conductors at a block7210.

Referring now to FIGS. 7M and 7AK, in some embodiments at least oneportion of an electrically conductive reactor coolant may be diverted ata block 7212.

For example and referring additionally to FIG. 7AL, in some embodimentsdiverting at least one portion of an electrically conductive reactorcoolant at the block 7212 may include diverting the at least one portionof the electrically conductive reactor coolant along at least one of aplurality of diversion flow pathways extending from the electromagneticflow regulator to respective ones of a plurality of the nuclear fissionmodules at a block 7214.

As another example and referring now to FIGS. 7AI, 7AK, and 7AM, in someother embodiments diverting at least one portion of an electricallyconductive reactor coolant at the block 7212 may include diverting theat least one portion of the electrically conductive reactor coolantalong a diversion flow pathway bypassing the nuclear fission module at ablock 7216.

As another example and referring now to FIGS. 7AI, 7AK, and 7AN, in someother embodiments diverting at least one portion of an electricallyconductive reactor coolant at the block 7212 may include diverting theat least one portion of the electrically conductive reactor coolantalong a diversion flow pathway having a first direction and a seconddirection at a block 7218.

Referring now to FIGS. 7AI and 7AO, in some embodiments at least oneoperating parameter associated with the nuclear fission module may besensed at a block 7220.

Referring additionally to FIG. 7AP, in such cases electromagneticallyregulating flow of the electrically conductive reactor coolant to thenuclear fission module with an electromagnetic flow regulator coupled tothe nuclear fission module at the block 7206 may includeelectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module and responsive tothe operating parameter associated with the nuclear fission module at ablock 7222.

The operating parameter associated with the nuclear fission module mayinclude any parameter as desired. In various embodiments, the operatingparameter may include without limitation temperature, neutron flux,neutron fluence, a characteristic isotope, pressure, and/or flow rate ofthe electrically conductive reactor coolant.

In some other embodiments and referring to FIGS. 7AI and 7AQ, flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor at the block 7204 may include flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor, the nuclear fission module being associatedwith a burn wave present at a location relative to the nuclear fissionmodule, the burn wave having a width, at a block 7224.

Referring additionally to FIG. 7AR, in some such caseselectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module at the block 7224may include electromagnetically regulating flow of the electricallyconductive reactor coolant to the nuclear fission module with anelectromagnetic flow regulator coupled to the nuclear fission module inresponse to the burn wave present at the location relative to thenuclear fission module at a block 7226. For example and referringadditionally to FIG. 7AS, electromagnetically regulating flow of theelectrically conductive reactor coolant to the nuclear fission modulewith an electromagnetic flow regulator coupled to the nuclear fissionmodule in response to the burn wave present at the location relative tothe nuclear fission module at the block 7226 may includeelectromagnetically regulating flow of the electrically conductivereactor coolant to the nuclear fission module with an electromagneticflow regulator coupled to the nuclear fission module in response to thewidth of the burn wave at a block 7228.

Referring now to FIGS. 7AI and 7AT, in some embodiments flowingelectrically conductive reactor coolant to a nuclear fission module in anuclear fission reactor at the block 7204 may include flowingelectrically conductive reactor coolant to a plurality of nuclearfission modules defining a reactor core having a coolant flow zone at ablock 7230.

Referring to FIGS. 7AI and 7AU, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7204 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a single coolant flow zone at a block7232.

Referring to FIGS. 7AI and 7AV, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7204 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a plurality of coolant flow zones at ablock 71342.

Referring to FIGS. 7AI and 7AW, in some embodiments flowing electricallyconductive reactor coolant to a nuclear fission module in a nuclearfission reactor at the block 7204 may include flowing electricallyconductive reactor coolant to a plurality of nuclear fission modulesdefining a reactor core having a plurality of coolant flow zonesseparated by respective ones of a plurality of partitions at a block7236.

One skilled in the art will recognize that the herein describedcomponents (e.g., operations), devices, objects, and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are contemplated.Consequently, as used herein, the specific exemplars set forth and theaccompanying discussion are intended to be representative of their moregeneral classes. In general, use of any specific exemplar is intended tobe representative of its class, and the non-inclusion of specificcomponents (e.g., operations), devices, and objects should not be takenas limiting.

Moreover, those skilled in the art will appreciate that the foregoingspecific exemplary processes and/or devices and/or technologies arerepresentative of more general processes and/or devices and/ortechnologies taught elsewhere herein, such as in the claims filedherewith and/or elsewhere in the present application.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of the subject matter described herein.It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to claims containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that typically a disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms unless context dictates otherwise. For example, the phrase “Aor B” will be typically understood to include the possibilities of “A”or “B” or “A and B.”

With respect to the appended claims, those skilled in the art willappreciate that recited operations therein may generally be performed inany order. Also, although various operational flows are presented in asequence(s), it should be understood that the various operations may beperformed in other orders than those which are illustrated, or may beperformed concurrently. Examples of such alternate orderings may includeoverlapping, interleaved, interrupted, reordered, incremental,preparatory, supplemental, simultaneous, reverse, or other variantorderings, unless context dictates otherwise. Furthermore, terms like“responsive to,” “related to,” or other past-tense adjectives aregenerally not intended to exclude such variants, unless context dictatesotherwise.

Moreover, the various aspects and embodiments disclosed herein are forpurposes of illustration and are not intended to be limiting, with thetrue scope and spirit being indicated by the following claims.

1.-24. (canceled)
 25. A system for regulating flow of an electricallyconductive fluid, the system comprising: a source of electrical power;and an electromagnetic flow regulator for regulating flow of anelectrically conductive fluid, the electromagnetic flow regulator beingelectrically connectable to the source of electrical power, theelectromagnetic flow regulator including: a plurality of magneticconductors arranged in fixed relative location, the plurality ofmagnetic conductors defining therealong a fluid flow path for anelectrically conductive fluid and defining therethrough a fluid inletpath for the electrically conductive fluid that is substantiallyorthogonal to the fluid flow path; and a field generation windingcapable of carrying an electrical current, the field generation windingbeing electrically connectable to the source of electrical power, thefield generation winding being electromagnetically couplable to theplurality of magnetic conductors such that at least one magnetic fieldis generatable by the field generation winding at the fluid inlet path.26. The system of claim 25, wherein the fluid inlet path is furtherdefined by a plurality of flow holes defined in the plurality ofmagnetic conductors.
 27. The system of claim 25, wherein the fluid flowpath is further defined inboard of the plurality of magnetic conductors.28. The system of claim 25, wherein the field generation winding isdisposed outboard of the plurality of magnetic conductors.
 29. Thesystem of claim 28, wherein the field generation winding includes ahelical coil.
 30. The system of claim 28, wherein the field generationwinding includes a plurality of substantially circular coils.
 31. Thesystem of claim 28, further comprising: a plurality of magneticnonconductors attached to the frame and disposed between adjacent onesof the plurality of magnetic conductors.
 32. The system of claim 31,wherein the fluid flow path is further defined along the plurality ofmagnetic nonconductors.
 33. The system of claim 25, wherein the fieldgeneration winding includes a first plurality of electrical conductorsthat are disposed inboard of the plurality of magnetic conductors and asecond plurality of electrical conductors that are disposed outboard ofthe plurality of magnetic conductors.
 34. The system of claim 33,further comprising: a plurality of magnetic nonconductors attached tothe frame and disposed between adjacent ones of the plurality ofmagnetic conductors.
 35. The system of claim 34, wherein the fluid flowpath is further defined along the plurality of magnetic nonconductors.36. The system of claim 34, wherein the fluid inlet path is furtherdefined through the plurality of magnetic nonconductors.
 37. A systemfor regulating flow of an electrically conductive fluid, the systemcomprising: a source of electrical power; and an electromagnetic flowregulator for regulating flow of an electrically conductive fluid, theelectromagnetic flow regulator being electrically connectable to thesource of electrical power, the electromagnetic flow regulatorincluding: a frame; a plurality of magnetic conductors attached to theframe, the plurality of magnetic conductors defining therealong a fluidflow path for an electrically conductive fluid and defining therethrougha plurality of flow holes that define a fluid inlet path for theelectrically conductive fluid that is substantially orthogonal to thefluid flow path; and a field generation winding capable of carrying anelectrical current and disposed outboard of the plurality of magneticconductors, the field generation winding being electrically connectableto the source of electrical power, the field generation winding beingelectromagnetically couplable to the plurality of magnetic conductorssuch that at least one magnetic field is generatable by the fieldgeneration winding at the fluid inlet path.
 38. The system of claim 37,wherein the fluid flow path is further defined inboard of the pluralityof magnetic conductors.
 39. The system of claim 37, further comprising:a plurality of magnetic nonconductors attached to the frame and disposedbetween adjacent ones of the plurality of magnetic conductors.
 40. Thesystem of claim 39, wherein the fluid flow path is further defined alongthe plurality of magnetic nonconductors.
 41. The system of claim 40,wherein the fluid flow path is further defined inboard of the pluralityof magnetic nonconductors.
 42. The system of claim 37, wherein the fieldgeneration winding includes a helical coil.
 43. The system of claim 37,wherein the field generation winding includes a plurality ofsubstantially circular coils.
 44. A system for regulating flow of anelectrically conductive fluid, the system comprising: a source ofelectrical power; and an electromagnetic flow regulator for regulatingflow of an electrically conductive fluid, the electromagnetic flowregulator including: a frame; a plurality of magnetic conductorsattached to the frame, the plurality of magnetic conductors definingtherealong a fluid flow path for an electrically conductive fluid anddefining therethrough a plurality of flow holes that define a fluidinlet path for the electrically conductive fluid that is substantiallyorthogonal to the fluid flow path; and a field generation windingincluding a first plurality of electrical conductors that are disposedinboard of the plurality of magnetic conductors and a second pluralityof electrical conductors that are disposed outboard of the plurality ofmagnetic conductors, the field generation winding being electricallyconnectable to the source of electrical power, the field generationwinding being electromagnetically couplable to the plurality of magneticconductors such that at least one magnetic field is generatable by thefield generation winding at the fluid inlet path.
 45. The system ofclaim 44, further comprising: a plurality of magnetic nonconductorsattached to the frame and disposed between adjacent ones of theplurality of magnetic conductors.
 46. The system of claim 45, whereinthe fluid flow path is further defined along the plurality of magneticnonconductors.
 47. The system of claim 45, wherein the fluid inlet pathis further defined through the plurality of magnetic nonconductors. 48.The system of claim 47, wherein the plurality of flow holes are furtherdefined through the plurality of magnetic nonconductors. 49.-354.(canceled)